Fixes bugs in left_sidebar app.

 On branch combined_dashboard
	modified:   app/assets/javascripts/backbone/lib/components/left_sidebar/left_sidebar_app.js.coffee
	modified:   app/assets/javascripts/backbone/lib/components/left_sidebar/show/show_controller.js.coffee
Changes channels app to use the header_sidebars layout.

 On branch combined_dashboard
	modified:   app/assets/javascripts/backbone/apps/channels/channels_app.js.coffee
	modified:   app/assets/javascripts/backbone/apps/channels/list/list_controller.js.coffee