fixes for the new res version

only for res 4.5.0.2. i won't accept any report for 4.5.0 - 4.5.0.1.

- added class `.edit-btn` to markdown editor toolbar button selectors to
  make them use our own style without using !important
- break down comment navigation sort buttons into two lines after the
  9th button and align the second line with the first line. it sucks, but
  better than letting it flow down below
- remove editor button style from macro dropdown toggler. it was added
  because it used to sit next to editor buttons and looked odd but now
  it's on its own area
- since the duplicate toolbar container in big editor now has a class,
  just hide the whole container instead of its contents
- remove absolute repositioning of "commenting as ..." in big editor
- re-force the current subreddit in shortcut bar to use our own color
- remove the bottom margin from comment. not specific to 4.5.0.2, res
  set bottom margin for comment since long ago