overrride group mode

[mnods]

we'd like an option in the plugin to overrride group mode. in moodle this is set at course level and the result is that collab sessions are usually set to whatever group mode is set, normally separate groups.

this is not how collab is generally used here but group mode is used for other things.

So should probably be a setting at global collab plugin level to set group mode to off.

cheers