Add a new SQL Server Management studio style tool for RDF Databases

[kal]

Imported from http://www.dotnetrdf.org/tracker/Issues/IssueDetail.aspx?id=267

Ron Michael Zettlemoyer has suggested that we create a new tool for managing RDF databases in the vein of SQL Server Management Studio

This tool would combine the functionalities of SPARQL GUI, rdfEditor and Store Manager into one single tool. It is proposed to build this tool in WPF to allow the existing editor infrastructure to be levaraged. Much of the Store Manager infrastructure can also be levaraged because the core of it is GUI agnostic and in a separate library.