Made Unity project directory structure more plugin compliant.
Added .sln for spine-csharp that compiles under MonoDevelop.  Modifie spine-csharp.csproj to compile under MonoDevelop (mac).
"using UnityEditor" is not necessary.
Merge pull request #31 from darktable/master

Reorganized Unity project to be more "plugin" compliant.
spine-unity ignore.
License headers.
Ignore
Refactoring to bring spine-libgdx up to date with spine-csharp and spine-xna.
Fixed spine-xns solution for VS2010.
Fixed cocos2d bounding box crash.