Remove code for PHP<5.3, use PHP_VERSION_ID instead of version_compare() for version checks

program/include/rcmail.php

@@ -173,7 +173,7 @@ class rcmail extends rcube
         setlocale(LC_ALL, $lang . '.utf8', $lang . '.UTF-8', 'en_US.utf8', 'en_US.UTF-8');
 
         // workaround for http://bugs.php.net/bug.php?id=18556
-        if (version_compare(PHP_VERSION, '5.5.0', '<') && in_array($lang, array('tr_TR', 'ku', 'az_AZ'))) {
+        if (PHP_VERSION_ID < 50500 && in_array($lang, array('tr_TR', 'ku', 'az_AZ'))) {
             setlocale(LC_CTYPE, 'en_US.utf8', 'en_US.UTF-8');
         }
     }

program/lib/Roundcube/rcube_utils.php

@@ -119,17 +119,6 @@ class rcube_utils
                 return true;
             }
 
-            if (strtoupper(substr(PHP_OS, 0, 3)) == 'WIN' && version_compare(PHP_VERSION, '5.3.0', '<')) {
-                $lookup = array();
-                @exec("nslookup -type=MX " . escapeshellarg($domain_part) . " 2>&1", $lookup);
-                foreach ($lookup as $line) {
-                    if (strpos($line, 'MX preference')) {
-                        return true;
-                    }
-                }
-                return false;
-            }
-
             // find MX record(s)
             if (!function_exists('getmxrr') || getmxrr($domain_part, $mx_records)) {
                 return true;

program/lib/Roundcube/rcube_washtml.php

@@ -378,7 +378,7 @@ class rcube_washtml
         $this->max_nesting_level = (int) @ini_get('xdebug.max_nesting_level');
 
         // Use optimizations if supported
-        if (version_compare(PHP_VERSION, '5.4.0', '>=')) {
+        if (PHP_VERSION_ID >= 50400) {
             @$node->loadHTML($html, LIBXML_PARSEHUGE | LIBXML_COMPACT);
         }
         else {