* [msbuild] Pack all iOS MSBuild Task assemblies into a single assembly
* Fixed the build
* Renamed ProcessArgumentBuilder to CommandLineArgumentBuilder
This is needed to prevent symbol conflicts with Xamarin.MacDev's
ProcessArgumentBuilder (which is functionally different from
Xamarin.MacDev.Tasks.Core's class of the same name).
* Fixed ILRepack logic for filtering dll's to repack
* Fixed building of Xamarin.iOS.Tasks.Tests now that X.iOS.Tasks.dll contains all symbols
* Updated Makefile now that only 1 iOS Task assembly needs to be distributed
* ILRepack Xamarin.Mac.Tasks as well
* Fixed up *.targets to specify The One Assembly To Rule Them All
* [xharness] Build MSBuild tests with MSBuild.
* Touch the ilrepack stamp file *after* invoking ILRepack, not before.
* Same for Xamarin.Mac.Tasks