User menu display

Second PR to review the user/group display
2 options added Show Users and All groups

To Test:
 * Log in as user-3
 * Click on "All Groups". All groups should be added to the display. 
 * Click on "Show All users item from All Groups. All the users should be added.
 * Check that all the users are selected in the group menu. e.g. read-annotate
 * De-select on "Show Users" in the main menu. Only group should be displayed. You will have to expand a   group to verify.
 * Select  "Show Users" in the main menu. Group and users should be displayed.