Reimplement Headers forEach that disappeared from Blink.
Use for-in iteration instead of Object.keys.forEach.
Merge branch 'separate-fix'

Conflicts:
	www/static/js-unmin/libs/cachedb.js
Add a trivial Selenium test.

This fails with a Service Worker-capable browser; see
https://code.google.com/p/chromedriver/issues/detail?id=920