Install PhpDocumentor via Composer. (#864)

build.xml

@@ -36,6 +36,8 @@
     <property name="mysqlpwswitch" value="-p" />
   </then></if>
 
+  <includepath classpath="${srcdir}/vendor/phpdocumentor" />
+
   <!-- Main Target -->
   <target name="main" description="main target">
     <phingcall target="startup" />

composer.json

@@ -35,6 +35,7 @@
         "behat/mink": "1.7.0",
         "behat/mink-selenium2-driver": "1.3.0",
         "friendsofphp/php-cs-fixer": "1.11.6",
+        "phpdocumentor/phpdocumentor": "2.8.5",
         "phploc/phploc": "2.0.6",
         "phpmd/phpmd": "2.4.2",
         "phpunit/phpunit": "4.8.27",