Adding event system when user is turned on or off -refs #6213
Merge remote-tracking branch 'chamilo.1.9.x/1.9.x' into yoselyn.6213
fixing event_system() call and improving performance -refs #6213
Removing sql query -refs #6213
Merge pull request #78 from ycastillo/yoselyn.6213

fixing event_system() call  and improving performance - refs #6213