misc polymer cleanups

Misc UI cleanups from the polymer changeover:

- fixed an issue where two menu item looked like hyperlinks when they weren't
- fixed an issue where the menu text was blurry (translate3d(0, 0, 0))
- fixed a font and sizing issue with the 'x' in the tabview tab headers
- save status, editor filename (in toolbar), and menu items all get the same font
- polymer splitter gets a little narrower, and the grab icon was removed (it was not centered, and didn't seem to be necessary)

@dinhviethoa @ussuri