FIXED: spine-csharp.csproj - Added missing files to project.
Merge pull request #219 from coeing/fix-project-file

FIXED: spine-csharp.csproj - Added missing files to project.
FIXED: spine-unity - Reverted meta file of SkeletonAnimation.cs to avoid loosing references in prefabs.
Merge pull request #220 from coeing/fix-SkeletonAnimation-meta

FIXED: spine-unity - Reverted meta file of SkeletonAnimation.cs to avoid...
Updated GUID.
Better reloading.
setPosition method.
Handle file being deleted.