Don't try to import proxy columns

Summary:
Fixes T10346. You finally wrung a clue out of the reporter and I think I figured this out.

Here's the bug:

  - Create a project with a workboard and subprojects/milestones.
  - Create a new project, import columns from the first project.
  - We incorrectly import empty columns for the subprojects/milestons.

Instead, skip proxy columns during import.

Also, allow "hide column" to continue on missing fields, so columns with no name can be hidden.

Test Plan:
  - Did the stuff above.
  - Workboard no longer populated with a bunch of "Unnamed Column" columns.
  - Hid several "Unnamed Column" columns.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10346

Differential Revision: https://secure.phabricator.com/D15265

src/applications/project/controller/PhabricatorProjectBoardImportController.php

@@ -50,6 +50,10 @@ final class PhabricatorProjectBoardImportController
         if ($import_column->isHidden()) {
           continue;
         }
+        if ($import_column->getProxy()) {
+          continue;
+        }
+
         $new_column = PhabricatorProjectColumn::initializeNewColumn($viewer)
           ->setSequence($import_column->getSequence())
           ->setProjectPHID($project->getPHID())

src/applications/project/controller/PhabricatorProjectColumnHideController.php

@@ -91,6 +91,7 @@ final class PhabricatorProjectColumnHideController
         $editor = id(new PhabricatorProjectColumnTransactionEditor())
           ->setActor($viewer)
           ->setContinueOnNoEffect(true)
+          ->setContinueOnMissingFields(true)
           ->setContentSourceFromRequest($request)
           ->applyTransactions($column, $xactions);
       }