Main change:
* Changed the native library to libSkiaSharp for Windows, UWP, Android, OSX and iOS
Issue #77#81
Other changes
* Updated the version number
* Use Android level 10 or v2.3 s the library version
* Update the docs
* Allow for the case where a custom libSkiaSharp is to be provided
* Make sure we have all the Android architectures
- created a generic/agnostic desktop build for both Mac and Windows
- using assembly configuration (dllmap windows dll to osx dylib)
- the .targets file uses '$(OS)' to import/copy the right files
- removed the double 'lib' prefix on osx
- added the desktop build to the NuGet
- using nunit 2 for XS compatibility
- bindings now reference the files in the ./native-builds/lib/ directory
- OS X no longer needs an explicit .dylib references, it just needs the .targets file
- cleaned up the unnecessary Android references
- moved Desktop & Driver projects into samples for later
- Cake now builds the C# libraries and samples
Matthew Leibowitz
Bill Holmes