Build for java 1.6 in case anybody's using that.
Browser invocation can be greatly simplified.

in Java 1.6+ and Scala 2.10+
Shared PortBindingInfo abstraction for all servers.

Includes `scheme`, `host`, and `port`, and produces a `url` so that
could be opened in a web browser.
Merge pull request #248 from unfiltered/port_bindings

Shared PortBindingInfo abstraction for all servers.