Add missing 'new migration' link

Addresses issue #399
Merge pull request #400 from deringer/dev

Add missing 'new migration' link
Update locale_de-DE.ini
Add missing dependencies
Merge pull request #401 from fanningert/patch-1

Update locale_de-DE.ini
Update german translation with PR #404
Merge pull request #405 from fanningert/patch-1

Update german translation with PR #404
Update locale_de-DE.ini and correct a wrong translation
Change "Repositories" to "Repositorys"
add Slack API webhook support
Update locale_de-DE.ini
Update locale_de-DE.ini
Update locale_de-DE.ini
Update deps
Merge pull request #379 from compressed/slack

Slack Support
Merge branch 'dev' of github.com:gogits/gogs into dev
Removed not needed deps

Removed
* github.com/gogits/cache
* github.com/gogits/session
Mirror fix and hide missing pages for 0.5 release
Merge pull request #402 from fanningert/patch-2

Add missing dependencies
Merge pull request #407 from fanningert/patch-3

Update locale_de-DE.ini and correct a wrong translation