Move Project transaction storage to modern tables

Summary:
Ref T4010. Projects have a weird proto-version of ApplicationTransactions which is very similar but not quite the same.

Move the storage to a modern format, but keep all the other code for now.

Test Plan: Migrated project transactions; edited projects.

Reviewers: btrahan, chad

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T4010

Differential Revision: https://secure.phabricator.com/D7370

src/applications/project/controller/PhabricatorProjectMembersEditController.php

@@ -54,7 +54,7 @@ final class PhabricatorProjectMembersEditController
       if ($changed_something) {
         $xaction = new PhabricatorProjectTransaction();
         $xaction->setTransactionType(
-          PhabricatorProjectTransactionType::TYPE_MEMBERS);
+          PhabricatorProjectTransaction::TYPE_MEMBERS);
         $xaction->setNewValue(array_keys($member_map));
         $xactions[] = $xaction;
       }