The Xamarin.MacDev.Tasks.sln solution is built with dotnet, while other projects
are still built with msbuild. This becomes a problem when generating Errors.designer.cs,
because depending on the runtime the output is different.
This means that the Errors.designer.cs will sometimes randomly change (depending
on which project re-generated the file), leaving the file modified in git. This is
quite annoying, but it also breaks the api comparison, which depends on the build
not leaving modified files behind. So for now, we generate Errors.designer.cs separately
for Xamarin.MacDev.Tasks.sln to not conflict with the mtouch version.
Also fix capitalization in numerous places to be consistent (it's Errors.designer.cs,
not Errors.Designer.cs).
73101f2689