c# projects: ignore user specific files, testresults and windows picture index files

CSharp.gitignore

@@ -5,3 +5,12 @@ _ReSharper*
 bin
 obj
 
+# user settings
+*.user
+*.suo
+
+# if you have pictures, windows will likely create those annoying index files
+Thumbs.db
+
+# mstest test results
+TestResults