Project hygiene

Project hygiene
- remove unused refs to System.Data.DataSetExtensions, System.Data,System.Linq.Xml
- warnings as errors
- mark as CLSCompliant so that it can be used in VB.Net and other .Net languages. And change expose ushort to int as this is not cls compliant as per http://stackoverflow.com/questions/3475726/argument-type-is-not-cls-compliant-why