Less specific selectors

I refactored the .scss files to make everything less-specific. (Davis Frank had an email thread with you from early October about this).

I've tested all the themes against the updated deck.core.css (both before and after the individual themes were made less-specific), including the "goto" and "menu" extensions, and it all looks good to me.

Let me know if you think I'm being ridiculous here. Thanks!