Fixes to swift-storage-source.yaml

Fixes to swift-storage-source.yaml

We've found a couple of bugs in swift-storage-source.yaml which
were exposed when we tried to use the template to build a second
Swift storage node.  These errors are:
a. Error in swift-devices metadata description - indentation
   wasn't correct and a "-" was missing
b. Keystone config data required by the swift-proxy element
   weren't defined
c. The signal_transport property wasn't defined and set to
   NO_SIGNAL for SwiftStorage0Deploy (this meant that the
   completion condition for the resource was never satisfied)
d. The user_data_format property for the SwiftStorage0
   resource was not defined and set to SOFTWARE_CONFIG, which
   meant that the SwiftStorage servers never got their config data
We've fixed the above errors.  We've added an
OS::Heat::StructuredConfig and corresponding
OS::Heat::StructuredDeployment for the Keystone config data.

Change-Id: I858ebf9eea4ed33987143277f4c986b4934555d1