Cleanup in src/, adding namespaces, removing php closing tag and general code cleanup

src/FactorGraphs/ScheduleStep.php

@@ -0,0 +1,21 @@
+<?php namespace Moserware\Skills\FactorGraphs;
+
+class ScheduleStep extends Schedule
+{
+    private $_factor;
+    private $_index;
+
+    public function __construct($name, Factor &$factor, $index)
+    {
+        parent::__construct($name);
+        $this->_factor = $factor;
+        $this->_index = $index;
+    }
+
+    public function visit($depth = -1, $maxDepth = 0)
+    {
+        $currentFactor = &$this->_factor;
+        $delta = $currentFactor->updateMessageIndex($this->_index);
+        return $delta;
+    }
+}