Conpherence Full modernize pass, setting standard space and colors on all widget panels. Moved menu back to 240px as the narrow column wasn't really usefull. Removed 'subtitle' on menu, seems simpler but almost under-designed. Subtitle isn't particularly useful and I plan on adding audience icons next (single, group, project, public) so I think this is the right direction.

Tested with and without number columns on the menu, test with files, calendar dates, removing participants.