doc: escape user.home example
configdrive: Use the EC2 metadata over OpenStack

Standardize on specific EC2 and OpenStack versions and add tests.
Merge pull request #188 from crawford/configdrive

configdrive: Use the EC2 metadata over OpenStack
coreos-cloudinit: bump to 0.9.1
coreos-cloudinit: bump to 0.9.1+git
datasource: Move datasources into their own packages.
timeouts: Use After() instead of Tick()
metadata: Refactor metadata service into ec2 metadata

Added more testing.