[FEATURE query-params-new] Don't eagerly init controllers

This uses the somewhat hacky approach of looking up
a controller class's proto() to read its queryParams
configuration without instantiating it (unless it's
already been instantiated).

/cc @stefanpenner @ebryn
Merge pull request #4261 from machty/non-eager-init

[FEATURE query-params-new] Don't eagerly init controllers