Author: Marina Glancy
MDL-52707 core_tag: allow to combine tags
http://git.moodle.org/gw?p=moodle.git;a=commit;h=0d2027896db2794ea88477859be08165510e170c
http://github.com/moodle/moodle/commit/0d2027896db2794ea88477859be08165510e170c
+ 3.1 en [combined,core_tag]
+ 3.1 en [combineselected,core_tag]
+ 3.1 en [nameuseddocombine,core_tag]
+ 3.1 en [selectmaintag,core_tag]
+ 3.1 en [selectmultipletags,core_tag]