Author: Rossiani Wijaya
MDL-34562 accessibility compliance for chat module: Add <label> for input text and select tag
http://git.moodle.org/gw?p=moodle.git;a=commit;h=2ab9801b192630508f26fb043b9bd4d04ef8f495
http://github.com/moodle/moodle/commit/2ab9801b192630508f26fb043b9bd4d04ef8f495
+ 2.3 en [entermessage,mod_chat]