Xamarin Forms Templates

This is an alternative version of the Xamarin Forms template.
It reduce errors at the time of project creation.

Based on @ytabuchi's Xamarin templates (http://ytabuchi.hatenablog.com/entry/vs-xf-template).

• Support installer (VSIX) & Visual Studio Gallery
• Reduce errors at the time of project creation
• Add some of the templates
  • Xamarin.Forms (Android/iOS)
  • Xamarin.Forms (UWP/Android/iOS)
  • Xamarin.Forms (UWP/Android/iOS/Win8.1/WP8.1)