Merge pull request #4 from vzsg/master

Android: crash on startup with 1.0.6.1 (and earlier)
NuGet packages updated to MvvmCross 3.2.1
All namespaces removed from 'MvvmCross.HotTuna.Plugins' to 'MvxPlugins'
Version increased to 1.0.7
nuspec corrected according to namespace changes
Implemented forward geocoding for Windows Phone.

And refactored the async wrapper while at it.
Oops, added disappeared file to the project.
Merge branch 'wpforwardgeocode' of https://github.com/vzsg/Mvx.Geocoder into wpforwardgeocode