[CORE][COMPOSER] Move extlib packages with immediate composer correspondent to composer dependencies

This adds a composer.json for all dependencies that are available

vendor/ezyang/htmlpurifier/library/HTMLPurifier/Token/Start.php

@@ -0,0 +1,10 @@
+<?php
+
+/**
+ * Concrete start token class.
+ */
+class HTMLPurifier_Token_Start extends HTMLPurifier_Token_Tag
+{
+}
+
+// vim: et sw=4 sts=4