Author: Eloy Lafuente (stronk7)
MDL-30007 standardise assignment subplugin lang files
http://git.moodle.org/gw?p=moodle.git;a=commit;h=59e6df28830cadbd0d3fdc138a01d86b4f4e5abe
http://github.com/moodle/moodle/commit/59e6df28830cadbd0d3fdc138a01d86b4f4e5abe
+ 2.2 en [pluginname,assignment_offline]
+ 2.2 en [pluginname,assignment_online]
+ 2.2 en [pluginname,assignment_upload]
+ 2.2 en [pluginname,assignment_uploadsingle]