Add required php and mysql versions to version.php. Future proof required version check strings. Props nacin. see #11464

git-svn-id: https://develop.svn.wordpress.org/trunk@12432 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/version.php

@@ -30,3 +30,17 @@ $tinymce_version = '327-1235';
  * @global string $manifest_version
  */
 $manifest_version = '20090616';
+
+/**
+ * Holds the required PHP version
+ *
+ * @global string $required_php_version
+ */
+$required_php_version = '4.3';
+
+/**
+ * Holds the required MySQL version
+ *
+ * @global string $required_mysql_version
+ */
+$required_mysql_version = '4.1.2';