Intellij collab plugin

Jetbrains is developing a long desired collaboration plugin. https://youtrack.jetbrains.com/issue/IDEABKL-708#focus=Comments-27-4365766.0-0

The plugin can be downloaded here without taking the survey.

Documentation can be found here.

@jansauer and I already had a very positive first test. Some features are still missing, but overall the plugin looks very promissing.