Use OMGHTTPURLRQ in Swift version

Since CocoaPods doesn’t properly support swift yet I had to Vendor OMGHTTPURLRQ :P
Split Swift files
Convert PMKRetain/PMKRelease to Swift
Alphabetize extension listings
Rather than Promise.when, simply when()

Since Swift has proper namespacing, this is nicer IMO.
Swift parity with objc close

After much thought I cannot figure out how to unify the codebases. Mostly due to the use of generics in the Swift version, which is too great to not have.

So I have just repeated myself, everywhere :(