- New 2x toolbar button shapes and other icons from @johanneskrtek --
this HiDPI-ifies basically all graphics other than a few remaining item
type icons
- Use the Mac search dropmarker for all menu buttons, since it's wider
and more pleasant. Reduce menu button padding slightly to compensate.
- Better toolbar button state for inactive window and pressed state
- Fix dropmarker overlap in tag selector icon
Closes#347, Better/retina-style OS X toolbar icons
Closes#1339, Create new button PNGs for macOS
