i-bem__dom: setMod doesn't add css class if blocks on the same DOM node have overlapping end parts in their names

[narqo]

/*
<div class="modal personal-modal i-bem"></div> 
*/

BemDom.decl('personal-modal', {
  onSetMod : {
    'js' : {
      'inited' : function() {
        var modal = this.findBlockOn('modal');
        modal.hasMod('js', 'inited');   // true
        modal.domElem.hasClass('modal_js_inited');  // false  (Oops!, no "modal_js_inited" class here)
      }
    }
});

I believe this className.indexOf(classPrefix) > -1 is the problem.

/cc @4ok

[dfilatov]

(' ' + className).indexOf(' ' + classPrefix) > -1