Register git repo in ide.
Support user notes on all experiment objects.

UI to be done.
Add UI for linking loops to data source.
Revert "Add nullable to project."

This reverts commit f79a3a3e0977795af010b6c6e49873ccf668bb37.
Display new loop UI.
Add missing copyright headers to most files.
Implement new loop features.
Keep loop up to date with data source changes.
Remove list dividers.
Align visible borders in program layouts.