acl 5.x-1.4

Bugs fixed:
o fixed acl_remove_user()
o Changed acl_has_users() to use a COUNT() query rather than db_affected_rows() which isn't always reliable on SELECT queries.
o fixed htmlspecialchars() warning if one removes the last user from an
o #135684 follow up, fixes denying access only to nodes that are assigned to an
o #135684 implement hook node grants and some other improvements
o #124070: acl_add_user had a typo preventing it from working.
o #124088: E_ALL fix in acl_edit_form