Use --user and --password from bin/storage in PHP migrations

Summary:
Fixes T2059. Ref T2517.

Currently, you can run `bin/storage upgrade` with `--user` and `--password` arguments. However, these clownishly apply only to `.sql` patches -- the `.php` migrations still use the default user and password.

This is dumb. Stop doing it. Respect `--user` and `--password` for PHP patches.

(I implemented "override", which is very similar to "repair", but kept them separate since I think they're semantically distinct enough to differentiate.)

Test Plan: Ran `./bin/storage upgrade --user x --pass y --apply phabricator:20130219.commitsummarymig.php`. Verified the correct user and password were used both for the initial connect and patch application.

Reviewers: chad, vrana

Reviewed By: chad

CC: aran

Maniphest Tasks: T2059, T2517

Differential Revision: https://secure.phabricator.com/D5115

scripts/sql/manage_storage.php

@@ -75,10 +75,12 @@ if ($args->getArg('password') === null) {
 } else {
   // Put this in a PhutilOpaqueEnvelope.
   $password = new PhutilOpaqueEnvelope($args->getArg('password'));
+  PhabricatorEnv::overrideConfig('mysql.pass', $args->getArg('password'));
 }
 
 $api = new PhabricatorStorageManagementAPI();
 $api->setUser($args->getArg('user'));
+PhabricatorEnv::overrideConfig('mysql.user', $args->getArg('user'));
 $api->setHost($default_host);
 $api->setPassword($password);
 $api->setNamespace($args->getArg('namespace'));