Update search.php to allow multiple file types

Allows add-on developers to load the file manager with a comma separated list of extensions or file types rather than only a single file type or extension. For example:

ccm_launchFileManager('&fExtension=jpg,jpeg,png,webm,mp4');

or 

ccm_launchFileManager('&fType=' + ccmi18n_filemanager.FTYPE_VIDEO + ',' + ccmi18n_filemanager.FTYPE_IMAGE);