Merge pull request #341 from andytuba/btctip-cleanup

update modules.bitcoinTip with skeeto's refactoring, my refactoring, and my fixups
add !important to keyboard nav highlight class due to some subs breaking this via !important on .entry … :-\
further style fixes to keynav highlight to prevent subreddit styles from breaking it.
show bitcoinTip button after share button for posts
instead of at the end, after [l+c]