Adds checks for mcrypt module for RINO2

- check for module on install
- check for module when RINO2 is enabled in admin
- check for module when RINO2 is used in communications

include/items.php

@@ -2000,6 +2000,8 @@ function dfrn_deliver($owner,$contact,$atom, $dissolve = false) {
 
 	$rino = get_config('system','rino_encrypt');
 	$rino = intval($rino);
+	// use RINO1 if mcrypt isn't installed and RINO2 was selected
+	if ($rino==2 and !function_exists('mcrypt_create_iv')) $rino=1;
 
 	logger("Local rino version: ". $rino, LOGGER_DEBUG);