Fix broken debouncing on search control textbox

The issue was that the triggerSearch event wasn't debounced until after the call to the super constructor. This meant that the event was already bound to the non-debounced version of triggerSearch before triggerSearch became debounced. I changed the ordering and added a new _triggerSearch method for clarity.

Signed-off-by: Don Naegely <naegelyd@gmail.com>
Merge pull request #503 from cbmi/issue-502

Fix broken debouncing on search control textbox