Updated this tool so that it should deal correctly with sub-groups that are already present + fixed the bug Djeroek mentioned:
renoise 3.1.1
-0.2
-Fixed issue when subgroups were selected, they would be dismantled by the tool.
-If there is no selection in the pattern, tool will now default to adding a group at the (cursor) selected track
-Fixed bug where if selection is made on master track or beyond, the tool would fire an error
DELETED DUE TO LUA API BUG DISCUSSED IN NEXT POST
related API bug that needed working around: