Added support for BulkInsert and InsertFrom

This update includes support for:
* BulkInsert of an IEnumerable<TEntity> into a single table
* InsertFrom to insert records into one table based on a select statement (SQL Server 'insert from' syntax)
* To support BulkInsert / InsertFrom, added support for multiple mapping fragments and constant property values
* Improved schema name detection
* Updated Microsoft's DynamicQuery code to include additional operations, including "IsType" (OfType), and "In", as well as a generic version of Select and additional options for OrderBy / OrderByDescending