Access refactor

Some comments and improvements for migrations

New config keys in [mailer] section:
 - CERT_FILE: path to a certificate file.
 - KEY_FILE: path to a key file.

Conflicts:
	cmd/serve.go
	models/access.go
	models/migrations/migrations.go
	models/org.go
	models/repo.go
	models/user.go
	modules/middleware/org.go
	modules/middleware/repo.go
	routers/api/v1/repo.go
	routers/org/teams.go
	routers/repo/http.go
	routers/user/home.go

This commit does a lot of the work of refactoring the access table in a table with id's instead of strings.

The result does compile, but has not been tested. It may eat your kittens.

Collaboration

Changes to repo-header-download-drop

- conf/locale: update Japanese locale

Fixes #921

Fix #922

Fixes #921 and makes the Mention regexp be in line with the others

Link to previous commited source file (diff.view_file button) instead of returning 404 for deleted files.

- routers/admin: add rewrite update hook operation
- conf/locale: update locale file due to ini behavior changes
- cmd/cert_stub.go: remove useless code
- cmd/fix.go: no longer need fix command(at least now)

Add option to provide configuration file on command line

Updated gogs.css - monospace font for hash

Updated gogs.css to use monospaced font for sha hash label in repository view to make it look nicer because of equal label width.

allow http push by token - #842

Make Signup button display configurable - #884

- models/issue.go: format comment type names