Revert "Move browser over to java.net.URLConnection."

This reverts commit c5c87615b9745516ab50d12306d0230b5c4fc990.
Revert "Log an error when no activity is found to handle a URL."

This reverts commit 73814c1b5f98ef81e22414f8465fc078bc68da52.
Revert "Rewrite calls to Proxy.getPreferredHttpHost"

This reverts commit be3afd1d19753881931852485050c400dcab5a10.