conexusmm 0.3.0 released

This release adds a few new progress widgets such as Spinner and ProgressBar to the toolset. Both widgets can have conexus endpoints attached and will provide feedback (spinning or pulsing) based on the data flow through the endpoint. Additionally, the EndpointStopButton has been rewritten adding a little more functionality, and the Conexusmm namespace has been changed to ConexusGtk to match the Papyrus and Bit libraries.