Style image page

1. Styled image details page to match the design
2. Added Myriad Pro font from Adobe TypeKit to match the mockups (Monica is using Myriad Pro in Illustrator design)
3. Imported voting and star icons from Illustrator.  They're not used yet, but now they can be.
4. Fixed the volume attach/detach/destroy functionality.  Apparently it was broken because the volume model wasn't modifying it's attach_data property correctly.
5. Removed help icons w/ descriptive text from page headers.  I think we should take it out because users don't need to see it once they understand how the app works, and if we have to explain what things are in long text then we've done something wrong.  I'd rather add short popovers where they're helpful than provide a lengthy description of a pages purpose.