Closes #2764

Also changes the avatar from a jpeg to a png, to allow for
transparent background. The indexed png is also smaller in size.

Note that at the moment the default avatar is only used when
the user requested a custom avatar and the custom avatar file
is not found (should never happen).

In the future the default avatar could be used as a default
return when by-mail avatar lookups fail too (both gravatar
and libravatar support passing a default)

- Update locale bindata

Closes #3192

use 'official' repo.Name instead of incoming repoName; to enforce
correct capitalisation

As you included Czech translation to official distribution, I think I'm missing here.
I know, selfish as hell... ;)

Always send user to settings screen to change avatar.
Drops "change_custom_avatar" localized message, keeps "change_avatar"
for the generic one.

NOTE: only changes the en-US locale, as per
https://github.com/gogits/gogs/wiki/Contributing-Code#those-we-do-not-accept

NOTE: requires rebuild of bindata.go to fully see effects

From https://godoc.org/crypto/tls#Config

    ServerName is used to verify the hostname on the returned
    certificates unless InsecureSkipVerify is given. It is also included
    in the client's handshake to support virtual hosting unless it is
    an IP address.

This is needed for certificate validation without InsecureSkipVerify.

* Do not write HTML in text/plain mail part

Fixes #2928

* Pass text/plain first, text/html second

* Do not send plain/text email if html2text failed (untested)

Add start count corrector for Repository.NumClosedIssues

Build only work with the current master of the package. Otherwise, I get this error.
```
...
# github.com/gogits/gogs/routers/api/v1/convert
routers/api/v1/convert/convert.go:200: undefined: gogs.Team
routers/api/v1/convert/convert.go:201: undefined: gogs.Team
...
```

* docker: update build script to use glide + make

- docker/build.sh will now use glide to fetch dependencies
- glide is built from source to keep compatibility with arm
  (no pre-prebuilt binary for arm)
- docker/build.sh will also now use the provided Makefile
  It will generate an error when trying to get git build has as we do
  not ship the 88mo .git directory during the build (should not cause
  any problem as the variable it sets was not set previously)

* docker: fix docker arm build

- drop gosu version back to 1.7 as gosu binary for armhf is broken
- see tianon/gosu#19

* docker: update gosu to 1.9

Signed-off-by: Jean-Philippe Roemer <jp@roemer.im>

- Prevent panic on creating notice if database is not available
- Prevent incorrect folder on Windows ("/" instead of "\")

- Update language choose dropdown to fit more languages

* Add and start jQuery AreYouSure

* Update SimpleMDE to 1.10.1 for `forceSync` support

* Forgot to remove old version SimpleMDE 1.10.0

* formatting -.-

- Created a Container options section in `docker/README.md`
- Add documentation for SOCAT_LINK
- Move CROND documentation to the new section

Update ISC license

Reduce line number creation to one DOM manipulation