Display service extended to provide DIP

Program Forms controls by specifying inches -> display converts them to
device specific pixel value
Merge branch 'master' of https://github.com/XForms/XForms-Toolkit

Conflicts:
	samples/XForms.Toolkit.Sample/App.cs
	samples/XForms.Toolkit.Sample/XForms.Toolkit.Sample.csproj
Added screenshots for device independent size
Quick hack to get geolocation on WP8 working

Geolocator on WP8 does not support cancellation with the geolocator so
before looking into alternatives I put in a quick hack for the
cancellation.
Added gyroscopes to devices
Updated WP8 geolocation result to include time
Added camera view back
Initial Support for a Global "App" class with support for basic common events.
Merge branch 'master' of https://github.com/XForms/XForms-Toolkit

Conflicts:
	samples/XForms.Toolkit.Sample.Droid/MainActivity.cs
	samples/XForms.Toolkit.Sample.WP/App.xaml.cs
	samples/XForms.Toolkit.Sample.iOS/AppDelegate.cs
	samples/XForms.Toolkit.Sample/App.cs
Initial Support for automatically building nuget packages
Added nuget package scripts