feature: Allow customisation of rrd step/heartbeat when creating new rrd files (#5947)

* feature: Allow customisation of rrd step/heartbeat when creating new rrd files

* revert defaults

* added docs + webui config option

* Move RrdDefinition to an Object to make them easier to create and remove the possibility of typos.

* Fix style/lint issues and missing use statements

* 3 more missing use statements

* updated doc + moved schema file

LibreNMS/Exceptions/InvalidRrdTypeException.php

@@ -0,0 +1,31 @@
+<?php
+/**
+ * InvalidRrdTypeException.php
+ *
+ * -Description-
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @package    LibreNMS
+ * @link       http://librenms.org
+ * @copyright  2017 Tony Murray
+ * @author     Tony Murray <murraytony@gmail.com>
+ */
+
+namespace LibreNMS\Exceptions;
+
+class InvalidRrdTypeException extends \Exception
+{
+
+}