In "arc land", rebase branches in natural order

Summary: Ref T13546. When "arc land" performs cascading rebases, do them in "feature1", "feature2", etc., order so they're easier to follow. The outcome is not dependent on execution order.

Test Plan: Landed a change which cascaded many other branches, saw more comprehensible update order.

Maniphest Tasks: T13546

Differential Revision: https://secure.phabricator.com/D21320

src/land/engine/ArcanistGitLandEngine.php

@@ -103,6 +103,11 @@ final class ArcanistGitLandEngine
       }
     }
 
+    // Sort the result so that branches are processed in natural order.
+    $names = array_keys($result);
+    natcasesort($names);
+    $result = array_select_keys($result, $names);
+
     return $result;
   }
 

src/land/engine/ArcanistLandEngine.php

@@ -140,6 +140,15 @@ abstract class ArcanistLandEngine extends Phobject {
     return $this->shouldKeep;
   }
 
+  final public function setStrategyArgument($strategy_argument) {
+    $this->strategyArgument = $strategy_argument;
+    return $this;
+  }
+
+  final public function getStrategyArgument() {
+    return $this->strategyArgument;
+  }
+
   final public function setStrategy($strategy) {
     $this->strategy = $strategy;
     return $this;

src/workflow/ArcanistWorkflow.php

@@ -2357,11 +2357,13 @@ abstract class ArcanistWorkflow extends Phobject {
       $prompts = $this->newPrompts();
       assert_instances_of($prompts, 'ArcanistPrompt');
 
+      // TODO: Move this somewhere modular.
+
       $prompts[] = $this->newPrompt('arc.state.stash')
         ->setDescription(
           pht(
             'Prompts the user to stash changes and continue when the '.
-            'working copy has untracked, uncommitted. or unstaged '.
+            'working copy has untracked, uncommitted, or unstaged '.
             'changes.'));
 
       // TODO: Swap to ArrayCheck?