Include excanvas so that IE will work for streaming view
Include excanvas so that IE will work for streaming view

flot needs excanvas on IE.  Fixes #283

CSGOpenSource/Kibana2,melexis/kibana,CSGOpenSource/Kibana2,melexis/kibana,CSGOpenSource/Kibana2,alphagov/Kibana,rashidkpc/kibana2,alphagov/Kibana,rashidkpc/kibana2,alphagov/Kibana,melexis/kibana,rashidkpc/kibana2,rashidkpc/kibana2