Correct plural forms

Hello!

Here's a patch for 6.x-0.3 version of your great module. When I started translating found incorrect message 'Deleted !num limit rules.', my patch provides correct plural forms handling.
In -dev version I cannot find node_limit_node_type() function anyway I hope you find this patch useful or, at least, will remember about translators ;)

Please write when you freeze translated strings - I'll try publish polish translation.