Allow Home and Dashboards to be uninstalled

Summary:
Ref T7143. This is the simplest fix for adding a new route for Home, at the cost of possibly letting users break instances. However:

  - It's kind of hard to get to the option to uninstall Home anyway.
  - It's hard to imagine anyone will really uninstall Home by accident, right? Right?
  - Put a really scary warning on the action just in case.

Dashboards was only required because Home was required, I think, so just drop that too.

Test Plan: Uninstalled home.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: chad, epriestley

Maniphest Tasks: T7143

Differential Revision: https://secure.phabricator.com/D11753

src/applications/dashboard/application/PhabricatorDashboardApplication.php

@@ -55,8 +55,4 @@ final class PhabricatorDashboardApplication extends PhabricatorApplication {
     );
   }
 
-  public function canUninstall() {
-    return false;
-  }
-
 }

src/applications/home/application/PhabricatorHomeApplication.php

@@ -34,10 +34,6 @@ final class PhabricatorHomeApplication extends PhabricatorApplication {
     return false;
   }
 
-  public function canUninstall() {
-    return false;
-  }
-
   public function getApplicationOrder() {
     return 9;
   }

src/applications/meta/controller/PhabricatorApplicationUninstallController.php

@@ -63,10 +63,28 @@ final class PhabricatorApplicationUninstallController
       }
     } else {
       if ($selected->canUninstall()) {
-        $dialog->setTitle('Confirmation')
+        $dialog->setTitle(pht('Really Uninstall Application?'));
-               ->appendChild(
+
-                 'Really Uninstall '.$selected->getName().' application?')
+        if ($selected instanceof PhabricatorHomeApplication) {
-               ->addSubmitButton('Uninstall');
+          $dialog
+            ->appendParagraph(
+              pht(
+                'Are you absolutely certain you want to uninstall the Home '.
+                'application?'))
+            ->appendParagraph(
+              pht(
+                'This is very unusual and will leave you without any '.
+                'content on the Phabricator home page. You should only '.
+                'do this if you are certain you know what you are doing.'))
+            ->addSubmitButton(pht('Completely Break Phabricator'));
+        } else {
+          $dialog
+            ->appendParagraph(
+              pht(
+                'Really uninstall the %s application?',
+                $selected->getName()))
+            ->addSubmitButton(pht('Uninstall'));
+        }
       } else {
         $dialog->setTitle('Information')
                ->appendChild(