Author: Jerome Mouneyrac
MDL-30268 add 'Can download files' field to service
http://git.moodle.org/gw?p=moodle.git;a=commit;h=af03513f9332bccda05ba723ac01a6373ecb0310
http://github.com/moodle/moodle/commit/af03513f9332bccda05ba723ac01a6373ecb0310
+ 2.2 en [downloadfiles,core_webservice]
+ 2.2 en [downloadfiles_help,core_webservice]