add disk queue files from NSQ

this will help with implementing spooling
files taken from https://github.com/bitly/nsq/tree/master/nsqd
expose needed disk queue stuff to other packages
implement routes with spooling

also:
* cleanup some messy/verbose fmt output
* refactor Route.relay()
simpler
better title/branding in web UI
if pattern doesn't compile, don't update regex
support updating remote addr (in web UI)
update to describe better limitations of interfaces