Beta Release with support for NetBox Branching

Warning

This is a beta release. Do not use it in production, and have a good backup at all times!

This release incorporates changes by @arthanson that should resolve the existing issues with NetBox Branching. I know this is what many of you have been waiting for, and I'm glad that Art made the effort of looking at the issues and fixing the conflicts with the branching plugin.

Please keep in mind that this is still a beta version! Normal operations (i.e. without Branching) shouldn't be a problem, but the plugin has not been tested with branching extensively and may still contain some bugs that can cause data corruption, loss or unmergeable branches. Please don't use it in production yet!