Merge pull request #74 from raistlinthewiz/blocked-sky

Implemented basic blocked sky.
Removed content project reference from Engine project.
Update Compatibility
Update README.md
Updated monogame dependencies against monogame/develop3d branch.
Updated monogame dependencies.
Moved platform related info to Platform/PlatformInfo.cs.
Moved VersionInfo.cs to Platform/.
Update README.md
Updated build/build-win-*.bat
Merge pull request #76 from kthompson/develop

Updated build/build-win-*.bat
Merge pull request #77 from raistlinthewiz/develop

Sync blocked-sky with develop branch.