[2.0] Fixes issue with optimistic timestamp locking (closes #2451)

lib/Doctrine/DBAL/Platforms/MySqlPlatform.php

@@ -264,7 +264,11 @@ class MySqlPlatform extends AbstractPlatform
      */
     public function getDateTimeTypeDeclarationSql(array $fieldDeclaration)
     {
-        return 'DATETIME';
+        if ($fieldDeclaration['version']) {
+            return 'TIMESTAMP';
+        } else {
+            return 'DATETIME';
+        }
     }
     
     /**

lib/Doctrine/ORM/Tools/SchemaTool.php

@@ -249,6 +249,7 @@ class SchemaTool
         $column['length'] = isset($mapping['length']) ? $mapping['length'] : null;
         $column['notnull'] = isset($mapping['nullable']) ? ! $mapping['nullable'] : false;
         $column['unique'] = isset($mapping['unique']) ? $mapping['unique'] : false;
+        $column['version'] = $class->isVersioned && $class->versionField == $mapping['fieldName'] ? true : false;
 
         if (isset($mapping['precision'])) {
             $column['precision'] = $mapping['precision'];