title: grouping input widgets in Shiny
body: <p>I'm building a Shiny app and I'd like to be able to group input widgets, preferably with a title for each group. For example, I'd like a box for "Pants size" with a drop-down for waist and a drop-down for inseam, and then another box for "T-shirt size" with a drop-down for XS/S/M/L/XL and radio buttons for unisex/women's.</p>
  
  <p>Is there a way to put sets of widgets in their own boxes, or to break up the standard grey box they all come in?</p>
  
  <p>Thanks!</p>