LPS-40856

Heya Chema, I'm sending this one back over to you with my changes. Here are the other changes we need to do for this one: 1. In Firefox, the menu dropdown arrow looks like this: http://cl.ly/image/442P1b0j3H3V 2. We need to move all of the Classic specific colors out of the staging_bar portlet CSS and put them in the Classic theme. Also, we need to make the staging bar *only* looks good in the current Classic theme. However, if the dockbar-split is disabled, or you're not using the Classic custom.css, the staging bar looks really broken. So we need to move all structural CSS for the staging bar from custom.css into the dockbar.css so everyone will be able to have it by default. So there's 2 scenarios to test: 1. no custom.css with the dockbar-split turned off and turned on,  and 2. inside of classic in both scenarios. Please let me know if you guys have any questions. Thanks guys\! /cc @ipeychev @juliocamarero