Adding styles for the different visiblitly states of the branding bar

- added each state to different pages
	- index: **inconspicous**
	- challenges: **userOnly**
	- concepts: **brandOnly**
	- challenge: **hidden**
	- all other pages: **standardVisibility**
- styled each state on each page
- noticing some problems with transitions, will fix

**Problem**
We need the branding controlling class to be more global (like on the **body** for instance) because it needs to be able to affect other elements on the page. When the bar is hidden, it needs to be able to slide up, and the other page elements *also* need to be able to slide up.

refs #2