[storm] Proposal: use Launchpad's merge proposal feature for code reviews

[James Henstridge]

At present we use the Launchpad bug tracker to manage code reviews for
Storm.  With the last Launchpad release, support was added for
commenting on branch merge proposals, so I was wondering if we'd like
to switch over to this feature for our code review.

Here is a quick run down of how things work:

1. On the page for your branch (e.g.
https://code.launchpad.net/~user/storm/branch), there is a link in the
actions menu called "Propose for merging".  Clicking on this will take
you to a form for creating the merge proposal.  By default, the
proposal will target the development focus branch for the project
(i.e. ~storm/storm/trunk), but you can change that if it makes sense.

2. For branches that are targeted by merge proposals, there will be a
"View landing candidates" item in the actions menu that displays all
pending merges for the branch.  For Storm's development focus, the
page is:

    https://code.launchpad.net/~storm/storm/trunk/+landing-candidates

3. Clicking the "view proposal details" link for a proposal will take
you to an info page for the proposal showing:
 * a list of the unmerged revisions
 * a list of comments, which may include votes (disapprove, approve or abstain)

You can also add comments/votes to the proposal from this page.

4. If you are subscribed to either of the branches and have elected to
receive code review emails, then you should receive email notification
of comments on the proposals and notification of new proposals
involving the branch.  So people involved in Storm code review would
be expected to subscribe to ~storm/storm/trunk, and people wanting
their branch reviewed to be subscribed to their branch.


One downside to this system is that there is not yet a way to add
comments to a branch merge proposal via email.  That is planned for
the next roll out though (probably in a bit less than a month).  If
that feature is a must have, then it'd probably be worth holding off
until then.

James.