Make projects for UniversalApp and Windows 8 App
Make WP8(Silverlight) project
PCL: Change target framework
Remove CoreTweet.Streaming.Reactive.net45
Update nuspec
Windows Phone library cannot be built with x64 MSBuild
fix
Use HttpClient in Win8.1/WP8.1/Win8
Merge branch 'master' into feature/universal2

Conflicts:
	CoreTweet.Streaming.Reactive.Pcl/Stream.cs
	CoreTweet/Internal/TokensBase.Async.cs
Fix bugs caused by 5021ebeb7c903dc2eee5057c7f29bad7b334394d
Merge pull request #57 from azyobuzin/feature/universal2

Improve multi platform support