initial vagrant configuration to deploy a jenkins server which can test PHP buttonmen code

This is almost all vagrant code --- it adds a second vagrant target, deploy/jenkins/Vagrantfile, which shares the puppet code in deploy/vagrant/, but uses a separate manifest to build a jenkins server rather than a buttonmen server.  There are also a couple of tiny syntax-error fixes to live code, which i committed to test whether jenkins would satisfactorily notice that they'd been fixed and which should be harmless.

Please verify that this doesn't in any way break the usual operation of deploy/vagrant/ to create a buttonmen VM, and accept it if that much seems okay.  Once it's in master, i'll add a second host at AWS so we can look at what it does.

Partially addresses #376, but i want a full implementation of run_buttonmen_tests and QUnit before we close it.