Snippets/Convert vectorMenu to vectorTabs

Description
Changes the drop-down menus to tabs in the porlets added by Extension:Vector.

Deprecated by Snippets/Toggle between dropdown menus and tabs.

Tips

 * The code only uncollapses the #p-cactions portlet by default. To (also) uncollapse the #p-variants portlet, replace (or add it to) the selector: ( '#p-variants, #p-cactions' ).
 * The code creates a gap between portlets. To remove the gap, change the marginLeft value to -1px.