Improved Art-Net 4 compatibility

As Art-Net 4 no longer supports broadcasting of DMX values, the BlenderDMX Addon must ensure to correctly advertise required DMX universes, in order to receive DMX from Art-Net 4 transmitters. Michael Wigard has deeply investigated this and improved the ArtPollReply, to conform to the specification.

MVR Export has been improved by eliminating a bug which could cause data to be duplicated during subsequent exports. The Python GDTF and MVR libraries have received a huge overhaul and are now included. Clearing Programmer should now result in fixtures to be set to their default values (if only one fixture type is being selected). When adding new fixtures to the scene, they should now have correct, default values from the very beginning.

Changelog:

• Prevent MVR persistence during export, to eliminate duplication during export
• Update to latest pygdtf and pymvr libraries
• Improvements to Art-Net 4 compatibility, thanks to Michael Wigard
• Ensure that Programmer Clear sets the fixtures to default values
• Ensure that fixture is set to default and rendered after being added to the scene