Added *.VC.db to Unity.gitignore, which is an auto generated IntelliSense file from VS2015 Update 2 (replacing the .sdf file).

Unity.gitignore

@@ -23,6 +23,7 @@ ExportedObj/
 *.svd
 *.pdb
 *.opendb
+*.VC.db
 
 # Unity3D generated meta files
 *.pidb.meta