Refactor homescreen AppManager

**The Good News** :angel:
- No additional hacking of CSS and JS of existing ConfirmDialog
- AppManager has its own JS, CSS and view now
- More polished UI (Not necessarily FFOS style, but please give feedback)

**The Bad News** :imp:
- Breaks the display of the selected app's icon
- Breaks deletion of apps (needs a confirmation screen, but otherwise easy to fix?)
- Breaks navigation to the mockup of bluetooth share view (should be redesigned anyway)

Got a bit carried away with the styling and refactoring but let me know what ya think!

See video: https://www.dropbox.com/s/f70afq6fb1835f3/ffos.m4v