Update Intel App Framework to use Windows Phone 8 own symbol font / font icons

Updated the Intel App Framework to v2.1.0, fixed Windows Phone 8 issues with the back button, added CSS rules (so that the Segoe UI symbol font is used) on Windows Phone 8 and UI improvements for all platforms.

__Details of user interface changes__

+ Text input box is now a 'search' input box
+ 'Enter' / 'Search' keyboard key performs a search on Windows Phone 8
+ favicons icon font (containing favourite and un-favourite symbols) used on Android and iOS
+ Navigation bar now shown on Android
+ Faves and star button are positioned on the right on the Navigation bar
+ Replaced heading 'Information' with 'Property Details'
+ Able to navigate between favourites and results
+ Changed styling (colour) of recent search result count 'badges'

Fixes #285