Prevent tests hang when ip_echo is down.

It was here before, but when I was changing the fixture the last time, I introduced this back. py.test touches everything to find a fixture, so it was touching the lazycached host
Merge pull request #736 from mfalesni/prevent_touching_error

Prevent tests hang when ip_echo is down.
Coverage of advanced search box in Hosts

Adds a new web_ui module which can operate the advanced search box.
Adds tests testing the advanced search box in Hosts section.