"Edit user group" link should not be presented when no user group is defined
Ask for confirmation before deleting a user group
Do not show table header it there were no user groups
Delete related user group assignments when deleting a user group
Order user groups in ascending order
Merge branch 'master' into configurableMenus

Conflicts:
	libraries/server_privileges.lib.php
Escape html
Add new JS file for server_user_groups
Merge pull request #554 from kasunchathuranga/configurableMenus

Improvements to configurable menus