Changed Core namespace from FataMirageWinRT to FataMirage

In order to start the cross-plattform effords, the WinRT was removed
from all the namespaces except the platform-specific files. You can also
already find an empty project for windows desktop
Cross-platfrom support

Finally! FataMirage now runs on Android, Windows Desktop and Windows RT.
To achive this, we had to restructure the whole project.