smarty 3.1.15

- removed native template driver
- updated to smarty 3.1.15, see:
http://code.google.com/p/smarty-php/source/browse/trunk/distribution/change_log.txt
todo:
- trace down E_NOTICEs for undefined variables in smarty templates
(right now they are suppressed @/src/system/template/view.php:46
- find shorthand attributes in smarty tags