Build Log Cleanup

This PR updates to the latest Protobuild which supports disabling build warnings.  I disabled the following warnings which generate 1000s of messages in the build logs:

 - Disabled missing XML comment warnings [CS1591](http://msdn.microsoft.com/en-us/library/zk18c1w9.aspx).
 - Disabled type conflicts across assemblies for WinPhone [CS0436](http://msdn.microsoft.com/en-us/library/h6ys1ykk.aspx).