adjust .gitignore for unity

http://forum.unity3d.com/threads/unity-and-git.141420/
Revert "switch to Unity"

This reverts commit 285e849d203227db639474041cc99cf22c2f4b29.
Revert "Revert "switch to Unity""

This reverts commit 9d5fff66977cf6f075d01839a745e78433ee6558.
i dont know what im doing anymore