This includes a few changes:
* The repo name -- and hence the Go modules -- changes from pulumi-fabric to pulumi.
* The Node.js SDK package changes from @pulumi/pulumi-fabric to just pulumi.
* The CLI is renamed from lumi to pulumi.
We are renaming Lumi to Pulumi Fabric. This change simply renames the
pulumi/lumi repo to pulumi/pulumi-fabric, without the CLI tools and other
changes that will follow soon afterwards.
On the first turn, we want to distinguish between a coroutine
running that owns its turn, and a coroutine that knows it doesn't
own the turn and is simply awaiting its turn. The old Meet logic
wasn't quite right; instead, we'll have the caller tell us this.
* Assert new things in new places.
* Log more interesting tidbits during evaluation.
* Invoke the OnStart hook before triggering initializers.
* Tolerate nil prev snapshots during deletion calculation.
* Handle and serialize missing resource IDs as output props.
* Return "done" flag from Rendezvous.Meet.
This change guts the deployment planning and execution process, a
necessary component of pulumi/lumi#90.
The major effect of this change is that resources are actually
connected to the live objects, instead of being snapshots taken at
inopportune moments in time.
