router: s/CNAME/CName to follow standard in app package
router/testing: implementing cname functions
provision/docker/provisioner*: adding SetCName method

This method instantiates the configured router and calls it in order to
set the application's CName
provision/provision.go: Created CNameManager interface
router/testing/router.go: added mutex in AddCName method
router: s/RemoveCName/UnsetCName/g

This standardizes the method names used in other places
router/hipache: removing all cname records instead of only one specific address

This task (of removing one specific address from a cname) is let to be
done by the RemoveRoute method, which should search by related cnames
and do the dirty work (this distinction of cnames and routes is done
only by hipache, that's why we don't split that task)
router: removing address parameter from UnsetCName
router: s/AddCName/SetCName/g

Standardizes with other packages
provisioner/docker: created UnsetCName method on provisioner

Calling router.UnsetCName on it.
router/hipache: storing cname and appname in redis.

This will allow the Add/RemoveRoute methods to also manage the cname
records
router: receiving app name in UnsetCName method
provision/docker/provisioner.go: passing app name to route.UnsetCName call