Revert "Rename gem files from standard name to a custom one."

This reverts commit cc436c971d1153c6fd123b270a133b423b9a0945.
Revert "Disable on-the-fly check of valid RubyGem dependencies."

This reverts commit 5938a59b2ff8f8de814eebaa6d8934234e9ed720.
Update gem files to sass@3.2 and compass@0.12