Revert "[MacPlatform] Remove some duplicated NSApplication.Init calls"

This reverts commit 38fae6de6fff4f62964e76584c4d33263575c0b1.
Revert "[Mac] Re-use root menu else MacOS messes up badly"

This reverts commit 38faab6daa5cff6b51a0f35c3b56bd35a357fa72.
Revert "[Mac] There can only be one (services menu)"

This reverts commit 118cde6cf4a11a206973c5643af0d46402b2b672.
Revert "[Mac] Use Cocoa for main menu, for great justice!"
Merge pull request #42 from Unity-Technologies/unity-staging

Revert pull request #41