Encoding of arrays in GET params.

**fix($http) change buildUrl to allow for better array support**

Arrays of length one would be sent a key-value pair (`{a:[1]}` -> `a=1`). On the server side an additional check would be required. Not all third party APIs have a check/autofix for this. Adding in `[]=` when value is an array fixes this issue (`{a:[1]}` -> `a[]=1`).