Add titles to all nav links

See merge request !313

Don't require omniauth to enable github importer

I noticed the github importer is only enabled when omniauth authentication is also enabled. That isn't actually necessary -- just the oauth keys from GitHub are required to be configured.

The fix for this is very simple.

See merge request !316

Improve web editor

* focus on web editor
* Make editor looks same for new and edit file
* Refactor editor JS
* Improved satellite logic for new files

See merge request !1441

File creation and editing refactored

* Refactored controllers/helpers/views related to blob resource
* make it possible to create new file in empty repository

Second step in building #1930

See merge request !1440

Bigger font-size for code browsing

See merge request !1439

Create first file from empty repository via UI. pt1

* Backend can now commit file to empty repository.
* Empty project UI has new file button

First step in building #1930

See merge request !1438

Redesign project avatar page

See merge request !1437

Notify participants on close or reopen of issue/mr

Fixes #1891

cc @sytse

See merge request !1436

Also refactor NotificationService a bit

Improve project icon UI

See merge request !1435

Remove default project icon

See merge request !1434

Project avatar

See merge request !1433