fix($resource): params should expand array values properly

Today, calling e.g. var R = $resource('/Path/:a'); R.get({a: 'foo', bar: ['baz1', 'baz2']}); results in a query
string like "/Path/doh?bar=baz1,baz2" which is undesirable. This commit enhances resource to use
$http to encode any non-url parameters resulting in a query string like "/Path/doh?bar=baz1&bar=baz2".

BREAKING CHANGE: if the server relied on the buggy behavior then either the
backend should be fixed or a simple serialization of the array should be done
on the client before calling the resource service.
fix($http): do not encode special characters `@$:,` in params

encodeURIComponent is too aggressive and doesn't follow http://www.ietf.org/rfc/rfc3986.txt
with regards to the character set (pchar) allowed in path segments so we need
this test to make sure that we don't over-encode the params and break stuff
like buzz api which uses @self.

This is has already been fixed in `$resource`. This commit fixes it in a same way
for `$http` as well.

BREAKING CHANGE: $http does follow RFC3986 and does not encode special characters
like `$@,:` in params. If your application needs to encode these characters, encode
them manually, before sending the request.