Cherry-pick fixes from master#841

Merged

Aguilex merged 3 commits intodotnet:d15-4from

jonpryor:jonp-d15-4-fixes

Sep 11, 2017

Commits on Sep 11, 2017

[Xamarin.Android.Build.Tasks] No .dll's in Release if Optimize != True (#749)

dellis1972
authored and
jonpryor
committed
[Xamarin.Android.Build.Tasks] Library project C# changes & Rebuilds (#764)

dellis1972
authored and
jonpryor
committed
[Xamarin.Android.Build.Tasks] DesignTimeBuild failure on Rebuilds (#757)

dellis1972
authored and
jonpryor
committed