* removes the HTTP classes from this project and uses p3k-http library instead
* reorganizes the XRay classes into a psr-4 compatible folder
* moves controller autoload into -dev in preparation for turning this into a library (#17)
* fields that should be URLs will now be omitted if the value was not a URL, such as when the value is `javascript:alert()`
* makes Mf2 class slightly more self-contained by duplicating the URL helper functions into it
* fixes tests to not cache responses in memcache