GetFieldAsBinary() not implemented in C#

[rhaden]

A binding for the GetFieldAsBinary?() method is not included in the C# bindings for GDAL.

I've attached test data to help resolve the issue. It's a Microsoft Access database with ESRI Personal Geodatabase formatting. There's an additional table called BinaryRecords? which contains two fields: an ID field and a field called BinaryData? which is of type "OLE Object" (Access' equivalent to a BLOB). The table contains three records, each of which has a 1024-byte-long value in the BinaryData? column.