* Add LDAP Key Synchronization feature

Signed-off-by: Magnus Lindvall <magnus@dnmgns.com>

* Add migration: add login source id column for public_key table

* Only update keys if needed

* Add function to only list pubkey synchronized from ldap

* Only list pub ssh keys synchronized from ldap. Do not sort strings as ExistsInSlice does it.

* Only get keys belonging to current login source id

* Set default login source id to 0

* Some minor cleanup. Add integration tests (updete dep testify)

There's one for git gc, why not git fsck too?

Also add a couple more trace logs to GitFsck to see progress

* Replace all ctx.Handle with ctx.ServerError or ctx.NotFound

* Change Handle(403) to NotFound, avoid using macaron's NotFound

* Change EncodePasswd to HashPassword

* Create test+benchmark for HashPassword

* Add commit count caching

* Small refactoring

* Add different key prefix for refs and commits

* Add configuratuion option to allow to change caching time or disable it

* hide unactive on explore users and some refactors

* fix test for removed Organizations

* fix test for removed Organizations

* fix imports

* fix logic bug

* refactor the toConds

* Rename TestOrganizations to TestSearchUsers and add tests for users

* fix other tests

* fix other tests

* fix watchers tests

* fix comments and remove unused code

* Remove redudant functions and code

* Webhooks for repo creation/deletion

* add createHookTask

* Add handles for GetSlackPayload and GetDiscordPayload

* add google+

* sort signin oauth2 providers based on the name so order is always the same

* update auth tip for google+

* add gitlab provider

* add bitbucket provider (and some go fmt)

* add twitter provider

* add facebook provider

* add dropbox provider

* add openid connect provider incl. new format of tips section in "Add New Source"

* lower the amount of disk storage for each session to prevent issues while building cross platform (and disk overflow)

* imports according to goimport and code style

* make it possible to set custom urls to gitlab and github provider (only these could have a different host)

* split up oauth2 into multiple files

* small typo in comment

* fix indention

* fix indentation

* fix new line before external import

* fix layout of signin part

* update "broken" dependency

* fix: Admin can see all private repositories on Explore page.

* refactor: fix session

* git: delegate all server-side Git hooks (#1623)

* create hooks directories

* take control hooks back

* fix lint

* bug fixed and minor changes

* fix imports style

* fix migration scripts

* initial stuff for oauth2 login, fails on:
* login button on the signIn page to start the OAuth2 flow and a callback for each provider
Only GitHub is implemented for now
* show login button only when the OAuth2 consumer is configured (and activated)
* create macaron group for oauth2 urls
* prevent net/http in modules (other then oauth2)
* use a new data sessions oauth2 folder for storing the oauth2 session data
* add missing 2FA when this is enabled on the user
* add password option for OAuth2 user , for use with git over http and login to the GUI
* add tip for registering a GitHub OAuth application
* at startup of Gitea register all configured providers and also on adding/deleting of new providers
* custom handling of errors in oauth2 request init + show better tip
* add ExternalLoginUser model and migration script to add it to database
* link a external account to an existing account (still need to handle wrong login and signup) and remove if user is removed
* remove the linked external account from the user his settings
* if user is unknown we allow him to register a new account or link it to some existing account
* sign up with button on signin page (als change OAuth2Provider structure so we can store basic stuff about providers)

* from gorilla/sessions docs:
"Important Note: If you aren't using gorilla/mux, you need to wrap your handlers with context.ClearHandler as or else you will leak memory!"
(we're using gorilla/sessions for storing oauth2 sessions)

* use updated goth lib that now supports getting the OAuth2 user if the AccessToken is still valid instead of re-authenticating (prevent flooding the OAuth2 provider)

* Add a process.Manager singleton with process.GetManager()

* Use process.GetManager everywhere

* Fix godoc comments for process module

* Increment process counter id after locking the mutex

* restrict creating organizations based on right on user

* revert bindata.go

* reverse vendor lib

* revert goimports change

* set AllowCreateOrganization default value to true

* revert locale

* added default value for AllowCreateOrganization

* fix typo in migration-comment

* fix comment

* add coments in migration

* Remove unused custom-alphabet feature of random string generator

Fix random string generator

Random string generator should return error if it fails to read random data via crypto/rand

* Fixes variable (un)initialization mixed assign
Update test GetRandomString

* golint fixed for modules/setting

* typo fixed and renamed UNIXSOCKET to UnixSocket

- Update import paths from github.com/go-gitea to code.gitea.io
- Fix import path for travis

See https://docs.travis-ci.com/user/languages/go#Go-Import-Path

* Write LDAP, SMTP, PAM, DLDAP back to all uppercase

* Fix type in unused constant name

* Other MixCased fixes

* Complete MixerCasing of template constants

* Re uppercase LTS and LDAPS suffixes

* Uppercase JSON suffix in constant names

* Proper case LoginNoType

* Prefix unexported template path constants with "tpl"

* Add support for federated avatars

Fixes #3105

Removes avatar fetching duplication code
Adds an "Enable Federated Avatar" checkbox in user settings
(defaults to unchecked)

Moves avatar settings all in the same form, making
local and remote avatars mutually exclusive

Renames UploadAvatarForm to AvatarForm
as it's not anymore only for uploading

* Run gofmt on all modified files

* Move Avatar form in its own page

* Add go-libravatar dependency to vendor/ dir

Hopefully helps with accepting the contribution.
See also #3214

* Revert "Add go-libravatar dependency to vendor/ dir"

This reverts commit a8cb93ae64.

* Make federated avatar setting a global configuration

Removes the per-user setting

* Move avatar handling back to base tool, disable federated avatar in offline mode

* Format, handle error

* Properly set fallback host

* Use unsupported github.com mirror for importing go-libravatar

* Remove comment showing life exists outside of github.com

... pity, but contribution would not be accepted otherwise

* Use Combo for Get and Post methods over /avatar

* FEDERATED_AVATAR -> ENABLE_FEDERATED_AVATAR

* Fix persistance of federated avatar lookup checkbox at install time

* Federated Avatars -> Enable Federated Avatars

* Use len(string) == 0 instead of string == ""

* Move import line where it belong

See
https://github.com/Unknwon/go-code-convention/blob/master/en-US/import_packages.md

Pity the import url is still the unofficial one, but oh well...

* Save a line (and waste much more expensive time)

* Remove redundant parens

* Remove an empty line

* Remove empty lines

* Reorder lines to make diff smaller

* Remove another newline

Unknwon review got me start a fight against newlines

* Move DISABLE_GRAVATAR and ENABLE_FEDERATED_AVATAR after OFFLINE_MODE

On re-reading the diff I figured what Unknwon meant here:
https://github.com/gogits/gogs/pull/3320/files#r73741106

* Remove newlines that weren't there before my intervention

Initially proposed by #2376 and fixes #3068 as well.

- update glide info

Both are possible on explore and admin panel