Bugfixes and improvements to shell and context

lib/Context.php

@@ -12,6 +12,9 @@ class Context
 
     protected $data = [];
 
+    protected $parent;
+
+    protected $shell;
 
     public function __construct($name=null, array $data=[])
     {
@@ -20,6 +23,28 @@ class Context
         $this->configure();
     }
 
+    public function setParent(Context $parent=null)
+    {
+        $this->parent = $parent;
+    }
+
+    public function getParent()
+    {
+        return $this->parent;
+    }
+
+    public function getRoot()
+    {
+        if (!$this->parent) {
+            return $this;
+        }
+        $node = $this;
+        while ($parent = $node->getParent()) {
+            $node = $parent;
+        }
+        return $parent;
+    }
+
     protected function configure()
     {
         // Override this to do setup stuff
@@ -52,6 +77,7 @@ class Context
     {
         $this->commands[$command] = $handler;
         $this->commandInfo[$command] = $info;
+        ksort($this->commands);
     }
 
     public function setCommandHelp($command, $help)