* Constraint.cs: marked methods internal to fix public API

* Constraint.cs: marked methods internal to fix public API
* ConstraintCollection.cs: to fix public API, use
DataTable.fInitInProgress to check whether initialization
of DataTable is in progress
* DataColumn.cs: added stubs for missing methods
* DataRowBuilder.cs: marked Table property internal to
fix public API
* DataSet.cs: removed extra empty destructor, marked
OnMergeFailed internal to fix public API
* DataTable.cs: use fInitInProgress field to hold init
status, to match MS.NET
* DataView.cs: added missing attributes on IsOpen

svn path=/trunk/mcs/; revision=28816