hygiene: small special:search refactor

* removed some unneeded members
** Grepped for usage through repo and extensions
* added isPowerSearch method
* pull search options out of search profile tabs
  and into its own method
* consistent creation of did you mean html

Change-Id: I0da81609e3bc685c971b85a08e228cdda4455c18
Merge "hygiene: small special:search refactor"