feature: allow scripts to be run from any working directory (#4437)

* feature: allow validate.php to be run from any working directory

* remove redundant realpath() call

* re-add realpath() to remove symbolic links

* realpath() isn't needed...

* chdir() in all php scripts in ./ and ./scripts/

* update-sql.php clearly is not used, as it was broken.

* Change some scripts to executable
Remove extra chdir() call in snmp-scan.php

* Missed console-ui.php
Kind of fixed console-ui.php help output

* Re-add newline

scripts/tune_port.php

@@ -1,6 +1,8 @@
 #!/usr/bin/env php
 <?php
 
+chdir(realpath(__DIR__ . '/..')); // cwd to the parent directory of this script
+
 require 'includes/defaults.inc.php';
 require 'config.php';
 require 'includes/definitions.inc.php';
@@ -26,3 +28,5 @@ foreach (dbFetchRows("SELECT `device_id`,`hostname` FROM `devices` WHERE `hostna
         rrdtool_tune('port', $rrdfile, $port['ifSpeed']);
     }
 }
+
+rrdtool_close();