Search UI fixes

[Leigh Honeywell]

Hi GnuCash folks,

I've submitted a one-line patch for one of the issues in this bug:

https://bugzilla.gnome.org/show_bug.cgi?id=602052

To change the "Case Insenstive?" button to a checkbox, as the current UI
is unclear.

Before I start working on the other portion of the bug, I just want to
confirm that the assignee (David Hampton) isn't working on somewhere it too.

There are a couple of other search UI bugs that I'll be working on under
the same github branch:

https://github.com/hypatia/gnucash/tree/search-usability

If anyone wants to collaborate, find me on irc.

Thanks!

-Leigh

--
Leigh Honeywell
http://hypatia.ca
@hypatiadotca