GDTF: standard fixture profiles

[hugoaboud]

First steps of beta version must implement Fixture Profiles. Such profiles must be defined through the GDTF standard.

In addition to the standard information, the profiles should reference:

• a Fixture Object, with 3D models, constraints and handlers
• a Fixture Class, which handles the update of the fixture object

The proposed addition must be documented here for reference. If those infos are not set, the addon must let the user pick them from a list then update the .GDTF file.

Addition of fixtures must change from Pick Class > Pick Model > Set Model Parameters to Pick Profile.

As an extra, an "Import" button that copies .GDTF files to the proper folder would be helpful.

[hugoaboud]

GDTF support is coming on beta.

The implementation differs a lot from the described above. There's a generic Fixture Class, which uses GDTF structure of Body, Base, Head and Beam. A more detailed documentation might be on the way.

Currently it doesn't support multiple heads neither color wheels. I'll try to implement it soon.