Author: Mark Nielsen
MDL-32690: Restore 1.9 backup into 2.X fails on missing assignment type
Solution is as follows:
* Allow unsupported subplugins to convert from Moodle1 to Moodle2
* On Moodle2 restore hide unsupported subplugins
* Graceful error message in assignment of unsupported subplugins
http://git.moodle.org/gw?p=moodle.git;a=commit;h=65d14146af4bc338a7e3db013a82ff911d8afc9a
http://github.com/moodle/moodle/commit/65d14146af4bc338a7e3db013a82ff911d8afc9a
+ 2.5 en [unsupportedsubplugin,mod_assignment]