commit 90d83d9d602c2b358449f5d787b91dea52a29111
author Nicolas Lacasse <nlacasse@google.com> Wed Dec 09 10:27:04 2015 -0800
committer Nicolas Lacasse <nlacasse@google.com> Wed Dec 09 10:27:04 2015 -0800
tree 9778bf709ec981f9d91731f6749ab4d4a1f12b7f
parent c928f7fbc1b0988de1600e28ac3f54b4212b7904

TBR: Use unique keys and not project names to determine equality.

Jiri used to assume that project names were unique.  Once we implement
importing remote manifests, that assumption becomes hard to enforce.

This CL adds a Key() method to projects which returns a new ProjectKey
type.  The key is currently a combination of the project's name and
remote, although this is easy to change in the future.

The Projects map is now a map[ProjectKey]Project.

There is still a lot of code that tries to lookup projects by their
name.  For instance:
* tools and hooks in the manifest both refer to their projects by name
* some command-line tools take a list of project names as arguments

To support these cases, I added two methods to Projects map:
* FindName, which returns all projects matching the name, and
* FindUnique, which returns a single project matching the name, or
  an error if none or many are found.

NOTE: This is *almost* the same CL as
https://vanadium-review.googlesource.com/#/c/18205/.  The only
difference is that we now call writeMetadata() inside
nullOperation.Run().  We need to do this to make sure the remotes in the
metadata file are always in sync with the remotes in the manifest,
otherwise the project keys will differ.

MultiPart: 1/2
Change-Id: I334ffed799e8900b01865da2211b2de4cd04e9bf