Added since RIA/Silverlight projects use this for generated code that doesn't...

Added since RIA/Silverlight projects use this for generated code that doesn't get added into source control.

Global/VisualStudio.gitignore

@@ -49,4 +49,5 @@ TestResults
 ClientBin
 stylecop.*
 ~$*
-*.dbmdl
\ No newline at end of file
+*.dbmdl
+Generated_Code #added for RIA/Silverlight projects