start transition to new independent menu to prepare for RB2.99
compatibility
removed all ui manager actions -> working with RB2.99
add toggle action to app menu + use toolbar for sidebar menu
revert the toolbar thing since it looks ugly with many themes, use a
decent icon instead
some cleanup
bring back the toolbar icon for RB<2.99
fix show correct toolbar icon
toolbar and menu preference options only for RB<2.99
fix is_rb3 check
Merge branch 'experimental'
fix translations