Author: Petr Skoda
MDL-28344 new option to prevent clickjacking via frame embedding
http://git.moodle.org/gw?p=moodle.git;a=commit;h=5c754932e767b5bbf8a957590b4f0a9fead1d5a4
http://github.com/moodle/moodle/commit/5c754932e767b5bbf8a957590b4f0a9fead1d5a4
+ 2.2 en [allowframembedding,core_admin]
+ 2.2 en [allowframembedding_help,core_admin]