Created an option for the presenter to be able to share webcams only

bigbluebutton-client/resources/config.xml.template

bigbluebutton-client/src/VideoconfModule.mxml

...rg/bigbluebutton/modules/videoconf/business/VideoProxy.as

...g/bigbluebutton/modules/videoconf/maps/VideoEventMap.mxml

.../bigbluebutton/modules/videoconf/views/ToolbarButton.mxml

...rg/bigbluebutton/modules/videoconf/views/VideoWindow.mxml

...gbluebutton/modules/viewers/views/StatusItemRenderer.mxml