Adding PATCH HTTP method and urlencode request data

[davidchang]

The ability to urlencode request data, by providing the boolean "urlEncodeRequestData" in the config object, as part of the issue: #1743

Setting default headers and a short method for PATCH requests, as part of the issue: #899

[IgorMinar]

there are lots of issues in this PR, just to list some:

1/ needs cleanup
2/ separate PATCH changes from other changes so that it's one commit per logical change
3/ needs to be rebase to master
4/ the urlencoding transformation is on by default, I don't think that it should be part of $http unless you have a compelling arguments for including it

please read: http://docs.angularjs.org/misc/contribute

[davidchang]

Retracting