clear cache shell script fix [0.15.2]

This version introduces multiple enhancements:

fixed error when try to call event when removing cached files

Details of additions/deletions below:
--------------------------------------------------------------

Modified:   /shell/clear_cache.php
            -- Updated --
                code convention changes, added skip events variable to true

Modified:   /Lib/loader.php
            -- Added --
                $skipEvents static variable
            -- Updated --
                callEvent to check that events are on or off

Modified:   /Lib/config.ini
            -- Modified --
                changed version from 0.15.1 to 0.15.2