Add hash history to isotope's filtering of All Extensions

[roseleaf]

instructions at: http://isotope.metafizzy.co/docs/hash-history-jquery-bbq.html

filtered views of the /extensions page should be linkable/sharable and navigable

[roseleaf]

Turns out this approach won't work as the docs rely on jquery-bbq which relies on hashchange in the URL, but ember uses hash for its routing. which keeps being a freakin problem.
So instead, this will need to be done with queryparams

Ember.FEATURES['query-params'] = true;