Author: Petr Škoda
MDL-41269 add standard log life time and add missing lang strings
http://git.moodle.org/gw?p=moodle.git;a=commit;h=30e55e9ac6d16e55ae14af698cb190361c776e70
http://github.com/moodle/moodle/commit/30e55e9ac6d16e55ae14af698cb190361c776e70
+ 2.7 en [buffersize,logstore_standard]