Make Signup button display configurable - #884

- models/issue.go: format comment type names

- modules/base/markdown.go: fix issue link issue
- routers/repo/view.go: remove useless code

- conf/locale: add mew translator profile

Fix user mention bug when parsing markdown documents

fix highlighting css for del code

new lines highlighting format

Referencing issues from commit messages is now possible.

fix lines highlighting at diff view

fix error at admin/config

- templates/user/settings: fix email panel nav highlight

fix settings/email html&css

Fix #819 by fetching the repository from db before updating

Code-wise: the fixing-part of the code now doesn't reference the issue any more, because this is done by the referencing-part of the code, which is called just before.

Fixes #462, #668, #732.

add a function to rewrite all public keys on admin request

Add Miguel de la Cruz as a translator