Rep 1159 valve spring

ZOMG VALVESPRING

For review and then merging into core_spring woo!

Integration tests aren't going to pass.
I use it in the VALVE2 banner, showing what version of repose is running as well as the jetty version. It's truly only pretty. We could take it out, but I really like the way it looks.

It shows up when doing `java -jar repose-valve.jar --help` or when the command line parameters are wrong.