MDL-26925 User selector: Set label when no results

Thanks to Jonathon Fowler for the fix!
Merge branch 'MDL-26925-master' of git://github.com/danpoltawski/moodle
Merge branch 'MDL-37459-master-fix' of https://github.com/damyon/moodle
MDL-37621 Assign: Apply admin defaults to all module settings. Added the 3 date based settings.

Version bump for new settings.

AMOS BEGIN
    MOV [defaultplugins,mod_assign],[defaultsettings,mod_assign]
    MOV [defaultplugins_help,mod_assign],[defaultsettings_help,mod_assign]
AMOS END