Author: Damyon Wiese
MDL-43854 Atto: Add collapse toolbar plugin
http://git.moodle.org/gw?p=moodle.git;a=commit;h=fcb5b5c473ed4465fac364c281f0e2c7b0346dbd
http://github.com/moodle/moodle/commit/fcb5b5c473ed4465fac364c281f0e2c7b0346dbd
+ 2.7 en [pluginname,atto_collapse]
+ 2.7 en [showmore,atto_collapse]
+ 2.7 en [showless,atto_collapse]
+ 2.7 en [settings,atto_collapse]
+ 2.7 en [showgroups,atto_collapse]
+ 2.7 en [showgroups_desc,atto_collapse]