Added a page to display buttons and sets

Resolves #912

http://jenkins.buttonweavers.com:8080/job/buttonmen-AdmiralJota/342/

This also involved tweaking the python client a bit, so that should be tested too.
Nit: for() { break; } is a little awkward when you're expecting a one-item list.  Not sure offhand what you can do about it, but it seems awkward.