Implement an autoloader (#4140)

* Implement an autoloader

When cleaning up classes for psr2, things got a bit unwieldy, so I implemented a class autoloader.
I created a PSR-0 compliant LibreNMS directory and moved all classes there that made sense.
Implemented LibreNMS\ClassLoader which supports adding manual class mappings

This reduces the file includes needed and only loads classes when needed.

* Add teh autoloader to graph.php

* Add a small bit of docs
Fix incomplete class in includes/discovery/functions.inc.php

html/pages/device/apps/ntp.inc.php

@@ -11,8 +11,7 @@
  * the source code distribution for details.
  */
 
-require_once "../includes/component.php";
-$component = new component();
+$component = new LibreNMS\Component();
 $options = array();
 $options['filter']['ignore'] = array('=',0);
 $options['type'] = 'ntp';

html/pages/device/overview.inc.php

@@ -32,9 +32,8 @@ echo('
     <div class="col-md-6">
 ');
 require 'includes/dev-overview-data.inc.php';
-use LibreNMS\Plugins;
 
-Plugins::call('device_overview_container', array($device));
+LibreNMS\Plugins::call('device_overview_container', array($device));
 
 require 'overview/ports.inc.php';
 echo('

html/pages/device/port.inc.php

@@ -88,8 +88,7 @@ if (dbFetchCell("SELECT COUNT(*) FROM `ports_vlans` WHERE `port_id` = '".$port['
 }
 
 // Are there any CBQoS components for this device?
-require_once "../includes/component.php";
-$component = new component();
+$component = new LibreNMS\Component();
 $options = array();         // Re-init array in case it has been declared previously.
 $options['filter']['type'] = array('=','Cisco-CBQOS');
 $components = $component->getComponents($device['device_id'], $options);

html/pages/device/routing/cisco-otv.inc.php

@@ -1,7 +1,6 @@
 <?php
 
-require_once "../includes/component.php";
-$component = new component();
+$component = new LibreNMS\Component();
 $options = array();
 $options['filter']['ignore'] = array('=',0);
 $options['type'] = 'Cisco-OTV';