Merge from trunk 2747:

- Install process now looks like goto/roma.
- Move install.tpl to goto template.
- add charset utf8 to fatal error function.
- Check php version on install and upgrade, and die if < 5. 


git-svn-id: http://piwigo.org/svn/branches/2.0@2748 68402e56-0260-453c-a942-63ccdbb3a9ee

upgrade.php

@@ -21,6 +21,12 @@
 // | USA.                                                                  |
 // +-----------------------------------------------------------------------+
 
+//check php version
+if (version_compare(PHP_VERSION, '5', '<'))
+{
+  die('Piwigo requires PHP 5 or above.');
+}
+
 define('PHPWG_ROOT_PATH', './');
 
 include_once(PHPWG_ROOT_PATH.'include/functions.inc.php');