[FEATURE query-params-new] Query params rewrite

See here for some examples: https://gist.github.com/machty/8167051

Depends on Handlebars subexpressions:
https://github.com/wycats/handlebars.js/pull/690
Merge pull request #4008 from machty/query-params-rewrite

[FEATURE query-params-new] Query params rewrite