Author: Paul Holden
MDL-81870 core: validate component during upgrade task savepoint.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=f113a68fdc885eb3b598af58d4e2b09cd3e96d94
http://github.com/moodle/moodle/commit/f113a68fdc885eb3b598af58d4e2b09cd3e96d94
+ 4.3 en [pluginnotexist,core_error]