provider/gce: Move package-level vars over to environ.go.
provider/gce: Make sure number of state machines is not zero.
provider/gce: Fix SetConfig to ensure updated attrs (e.g. defaults) get applied.
provider/gce: Add Arches to instance type definitions.
provider/gce: (hack alert) Temporarily work around incorrect simplestreams index (zones listed instead of regions).
provider/gce: Return the proper results and error from environ.Instances.
provider/gce: imageURL -> imageEndpoint.
provider/gce: Add a TODO about timeouts.
provider/gce: Filter zones using a trailing regex wild-card.
provider/gce: Use the proper disk image resource (partial) URL.
provider/gce: Send a network interface definition in new instance requests.
provider/gce: Initialize a map before inserting into it.
provider/gce: Use the correct op ID value in waitOperation.
provider/gce: Add a TODO.
provider/gce: Preserve the disk info across the addInstance call.