#309 Adjust :uri to comply with RFC2396

[cjbarre]

Fixes #309

:uri is now the url-encoded full url as discussed in the issue.

It is being run through the java.net.URI constructor after being url-encoded since the URI class implements the spec.

:path has been added to replace the previous usage of :uri for consumers of existing functionality.

Existing tests have been adjusted.

This is a breaking change fit for 4.x as it changes the meaning of :uri for existing consumers.