Allow projects to be set as policies

Summary:
  - Renames `PhabricatorPolicyQuery` to `PhabricatorPolicyAwareQuery` (a query which respects policy settings).
  - Introduces `PhabricatorPolicyQuery`, which loads available policies (e.g., "member of project X").
  - Introduces `PhabricatorPolicy`, which describes a policy.
  - Allows projects to be set as policies.
  - Allows Paste policies to be edited.
  - Covers crazy cases where you make projects depend on themselves or each other because you are a dastardly villan.

Test Plan: Set paste and project policies, including crazy policies like A -> B -> A, A -> A, etc.

Reviewers: vrana, btrahan

Reviewed By: vrana

CC: aran

Maniphest Tasks: T603

Differential Revision: https://secure.phabricator.com/D3476

src/applications/project/controller/PhabricatorProjectProfileEditController.php

@@ -154,6 +154,11 @@ final class PhabricatorProjectProfileEditController
     $title = 'Edit Project';
     $action = '/project/edit/'.$project->getID().'/';
 
+    $policies = id(new PhabricatorPolicyQuery())
+      ->setViewer($user)
+      ->setObject($project)
+      ->execute();
+
     $form = new AphrontFormView();
     $form
       ->setID('project-edit-form')
@@ -187,12 +192,14 @@ final class PhabricatorProjectProfileEditController
           ->setName('can_view')
           ->setCaption('Members can always view a project.')
           ->setPolicyObject($project)
+          ->setPolicies($policies)
           ->setCapability(PhabricatorPolicyCapability::CAN_VIEW))
       ->appendChild(
         id(new AphrontFormPolicyControl())
           ->setUser($user)
           ->setName('can_edit')
           ->setPolicyObject($project)
+          ->setPolicies($policies)
           ->setCapability(PhabricatorPolicyCapability::CAN_EDIT))
       ->appendChild(
         id(new AphrontFormPolicyControl())
@@ -201,6 +208,7 @@ final class PhabricatorProjectProfileEditController
           ->setCaption(
             'Users who can edit a project can always join a project.')
           ->setPolicyObject($project)
+          ->setPolicies($policies)
           ->setCapability(PhabricatorPolicyCapability::CAN_JOIN))
       ->appendChild(
         id(new AphrontFormMarkupControl())