Author: Sara Arjona
MDL-85433 singleactivity: Support multiple activities
http://git.moodle.org/gw?p=moodle.git;a=commit;h=c5d66da0076227a1ba831ecc57ab0d3012aa2f37
http://github.com/moodle/moodle/commit/c5d66da0076227a1ba831ecc57ab0d3012aa2f37
+ 5.1 en [plugin_description,format_singleactivity]
- 5.1 en [orphaned,format_singleactivity]
- 5.1 en [orphanedwarning,format_singleactivity]
- 5.1 en [warningchangeformat,format_singleactivity]