buildUrl uses JSON.stringify instead of toJSON method if it exists

[pdanpdan]

buildUrl uses JSON.stringify to convert objects to string for $http.get,
but this converts Date objects to a quote enclosed string:
JSON.stringify(new Date()) => ""2014-02-05T15:15:22.612Z""
(new Date()).toJSON() => "2014-02-05T15:40:48.080Z"
I think buildUrl should use the object's toJSON method if it exists
This also applies to other objects that provide toJSON methods

[circlingthesun]

Currently (1.3.0-build.2753+sha.f37a2da) buildUrl users angular.toJSON(). Dates however still get quoted and one ends up with URL's that look like http://localhost:6543/api/booking?from=%222014-05-23T00:46:00.710Z%22&staff_id=1&until=%222014-05-29T21:59:59.710Z%22"

[danbarua]

Duplicated at #8150