Bump to version 0.4.3.

Changelog:
* 77c5f8bb8cef5e21dc43cc34d65218465450de5a,
0858829d72bde3ad639edf61a68b461a3ecedaf7,
e0ea51e5abb17b07f3a28ac0169a1d995f103b57:  Added core styles for lists.
* 8b5af6c82fe9cb2d8a631342639782ba94bf6ad9: Update to Normalize 3.0.1
* 0a5b1cb985b0a1add4b2570ff6f320edcf6d6284: Typo/wording fixes and code
cleanups.