Updated examples, added onEnter method to contexts

lib/Context.php

@@ -66,6 +66,11 @@ class Context
         $this->findCommands();
     }
 
+    public function onEnter()
+    {
+    }
+
+
     protected function findCommands()
     {
         $refl = new \ReflectionClass(get_called_class());

lib/Shell.php

@@ -113,6 +113,7 @@ class Shell
         }
         $context->setShell($this);
         $this->context = $context;
+        $context->onEnter();
         $this->dispatchEvent(self::EVT_CONTEXT_CHANGED);
     }