This PR removes three command line parameters from Cloud-enabled Pulumi commands (`update` and `stack init`). Previously we required users to pass in `--organization`, `--repository`, and `--project`. But with the recent "Pulumi repository" changes, we can now get that from the Pulumi workspace. And the project name from the `Pulumi.yaml`.
This PR also fixes a bugs that block the Cloud-enabled CLI path: `update` was getting the stack name via `explicitOrCurrent`, but that fails if the current stack (e.g. the one just initialized in the cloud) doesn't exist on the local disk.
As for better handling of "current stack" and and Cloud-enabled commands, https://github.com/pulumi/pulumi/pull/493 and the PR to enable `stack select`, `stack rm`, and `stack ls` do a better job of handling situations like this.
Previously we used the word "Environment" as the term for a deployment
target, but since then we've started to use the term Stack. Adopt this
across the CLI.
From a user's point of view, there are a few changes:
1. The `env` verb has been renamed to `stack`
2. The `-e` and `--env` options to commands which operate on an
environment now take `-s` or `--stack` instead.
3. Becase of (2), the commands that used `-s` to display a summary now
only support passing the full option name (`--summary`).
On the local file system, we still store checkpoint data in the `env`
sub-folder under `.pulumi` (so we can reuse existing checkpoint files
that were written to the old folder)
