number of workers for swift-storage should be configurable

[Tom Haddon]

The number of workers for swift-storage should be configurable in the charms, as this can have a big effect on performance according to http://docs.openstack.org/developer/swift/deployment_guide.html#general-service-tuning (note that threads_per_disk for the object server may be more important per http://docs.openstack.org/developer/swift/deployment_guide.html#object-server-configuration )

mthaddon@mallory:~/repos/charms/public/precise/swift-storage$ bzr revno
27
mthaddon@mallory:~/repos/charms/public/precise/swift-storage$ bzr info
Standalone tree (format: 2a)
Location:
  branch root: .

Related branches:
  parent branch: bzr+ssh://bazaar.launchpad.net/+branch/charms/precise/swift-storage/
mthaddon@mallory:~/repos/charms/public/precise/swift-storage$ grep -r workers *
templates/container-server.conf:workers = 2
templates/account-server.conf:workers = 2
templates/object-server.conf:workers = 2
mthaddon@mallory:~/repos/charms/public/precise/swift-storage$