Author: Ilya Tregubov
MDL-75156 gradebook: Grade summary plugin (grade averages).
Also included updates for existing unit tests and navigation.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=b3e05d0e4e107f73d54e5526a35507d36999b5b5
http://github.com/moodle/moodle/commit/b3e05d0e4e107f73d54e5526a35507d36999b5b5
+ 4.1 en [pluginname,gradereport_summary]
+ 4.1 en [summary:view,gradereport_summary]
+ 4.1 en [privacy:metadata,gradereport_summary]