This shortcode is the part of of the extension "Compare" - shows products on compare in popup.
- ids: set using comma products IDs you want to show your customers to compare
- title: link text
- css_class: CSS class of the link for view customization
- help_title: text of the link on the popup header from the right
- help_link: link in popup header
- skin: skin for the table, read more about skins here
All columns for [woot_compare_btn] can be set in the tab "Settings"