Add simple OgrGeometryReader class Removed constant reference to OgrLayer Added OgrDatasource clone for multithreaded access.
Add simple OgrGeometryReader class
Removed constant reference to OgrLayer
Added OgrDatasource clone for multithreaded access.

nhvu1988/SharpMap,SharpMap/SharpMap,nhvu1988/SharpMap,SharpMap/SharpMap