1.0.3-pre

Prerelease of 1.0.3 depending on Xamarin.Forms 3.3.

Now uses the new IImageViewHandler API, glidex.forms no longer implements any custom renderers.

Other changes:

• Using class-parse and AndroidCodegenTarget=XAJavaInterop1 for a better glidex binding
• TargetFrameworkVersion=v8.1
• Now only using portable pdb files