Make pretty_checkbox method public, set cursor:pointer on the icon-checkbox

skins/elastic/styles/widgets/forms.less

@@ -857,6 +857,7 @@ input.icon-checkbox {
         margin: 0;
         display: inline;
         font-size: 1.2rem;
+        cursor: pointer;
 
         &:before {
             &:extend(.font-icon-class);

skins/elastic/ui.js

@@ -70,6 +70,7 @@ function rcube_elastic_ui()
     this.form_errors = form_errors;
     this.switch_nav_list = switch_nav_list;
     this.searchbar_init = searchbar_init;
+    this.pretty_checkbox = pretty_checkbox;
 
 
     // Initialize layout