storyboard implementation and various UI bug fixes

[tobiasstrebitzer]

Overview

Storyboard implementation, along with a major refactor of event delegation.

New Features

• Separate code from design to allow customizations without changing the code-base
• Auto-Layout implementation to use constraint-based view sizing (instead of complex layout calculations in code)

Bugfixes

• Hide navigation bar title on portrait phone.
• Shelf Item layout was broken under certain circumstances (especially after rotation).

Configuration

After merging, all UI-related changes done to settings.plist need to be re-done in the storyboard (e.g. colors, backgrounds, fonts etc...)

Bugs / Caveats

• I have tested the app on iOS 7.1 and iOS 8.3. I tried to ensure existing functionality is still working, but i can't guarantee 100%. Additional testing is very welcome.