Removing the search select in favor of radios

[noahmanger]

This makes the radio buttons the only way to change the search type. Changing the search type now works as expected.

Also, this hides the header search on the search results page, as well as changes the way you hide the header (now just set a variable on the template hide_header_search = true).

(Wasn't sure the style for template variables like this, so can change to fit the convention.)

[msecret]

@noahmanger I'm ready to merge once the test pass or its confirmed that it's a testing issue not a code issue.

[noahmanger]

Weird. Tests pass for me locally and the errors i'm seeing on Travis look unrelated to what this is doing.

[noahmanger]

Ugh. I can't tell why these tests are still failing. Anyone have ideas?

[jmcarp]

These look like probabilistic failures that aren't related to your changes--the tests are also passing locally for me (most of the time). I need to find some time to figure out why some tests are failing sporadically, but for now, merging this.