added the /search endpoint

The bookmarklet lookups existing annotation view a call like /store/search?uri=http://path/to/.
Every annotation doc has a property "uri".
The view "annotationsbyUri" indexes all annotation docs about that property.

The specs https://github.com/okfn/annotator/wiki/Storage#search describing the expected response.
Because of the standard response of the view is different to that expectation - the response
gets finally formated in the list function "search".

In the rewrite rules the new endpoint /search is included. It forwards to the list/view path.
Also the query param "uri" gets rewritten to "key".