Added Shared Unit test files
Added Android Tests
Added C# Android Wrapper

Due to a resource generation issue in F# Android the tests have to be
wrapped by C# for now.
See https://bugzilla.xamarin.com/show_bug.cgi?id=17390
Added iOS Tests
Added Solution file
Updated .gitignore
Merge pull request #247 from 7sharp9/xplat-tests

Xplat tests