update secret structure
add passwords for master metabbotcfg
Merge pull request #39 from sa2ajj/add-other-slaves

add passwords for buildslaves used in master branch of metabbotcfg
add supervisor roles

supervisor

* add supervisor package
* config it
* enable and start supervisor daemon
* the role has a parameter -- services -- a list of supervisor services
  to be created: see roles/supervisor/templates/service.conf.j2 for
  parameter list (probably should go to a overall doc of sort)

supervisor-service

* to be documented
add virtualenv role
add bb-master role (wip)
add user role (wip)
add more params to proxy config
start working on actual configuration of nine.bb.net