Added support for multi-select comboboxes
Added support for multi-select comboboxes

Multi-select comboboxes fire the change event when un-selecting items in
the combobox which causes problems when we're only listening on the
select event with extjs4

murrah/glujs,murrah/glujs,codekoala/glujs,codekoala/glujs,murrah/glujs,CoNarrative/glujs,CoNarrative/glujs,codekoala/glujs,CoNarrative/glujs,murrah/glujs