Create Casopis-Podzemna-voda.csl

My first style, it is for the scientific magazine "Podzemna voda" (in slovak language, online: http://sah-podzemnavoda.sk/cms/page.php?9). It was created by adapting the existing style ISO-690 (author-date, Czech) (http://www.zotero.org/styles/iso690-author-date-cs).