Tazel no longer puts a publisher, a name or a version into the
descriptor of a plugin JAR (plugin API 3): who a plugin is comes from
ViGet, which records it when the plugin is pushed, or from the path of
a localPlugin.

- viget publish-tazel-plugin takes <Publisher> <Name> <Version> <jar>.
- TazelPluginDescriptor.TryRead and TazelPluginPublishing.PublishAsync
  take the three from the caller and check them as before: one
  identifier each for publisher and name, an exact version of three to
  five numbers.
- A descriptor that holds publisher, name or version is refused, with
  the keys it names.
- ops/README.md shows the new command line.

ViGet opens in stages: first only Progmasoft publishes Tazel plugins, later
every account. This adds the catalog and the server-side publishing for the
first stage; nothing publishes through the API yet.

- ViGet/: the catalog of Tazel plugins (in memory, or in PostgreSQL beside
  the accounts with its own numbered schema steps), the descriptor read from
  the JAR (META-INF/tazel-plugin.properties, with a reader of the Java
  properties format, and the ProjectPlugin service entry), and publishing:
  the publisher must be in ViGet:TazelPublishers (Progmasoft for now) and an
  existing account of that exact name, a version is never replaced, names
  that differ only in letter case are refused, and ViGet needs a
  description, an author and a license. The JAR is kept at
  dslplugins/tazel/<Publisher>/<Name>/<Version>/<Name>-<Version>.jar below
  ViGet:ArtifactRoot.
- Read endpoints under /api/v1/viget/dslplugins/tazel: the list, a plugin,
  and index.json, the index Tazel reads.
- 'viget publish-tazel-plugin <jar>' and 'viget yank-tazel-plugin' run with
  the configuration of the service instead of the service.
- The account store can find an account by name.

The pages, the Nginx routes and the deployment follow.