New Heading wizard for JQM 1.4

See http://demos.jquerymobile.com/1.4.0/body-bar-classes/

Heading and accompanying section can be arranged in 3 ways

• Default - they just follow each other and are marked up independently;
• Combined - they both belong to the same container that is marked up;
• Attached - the parent container provides custom rounded corners.

Other inputs:

• Label for heading;
• Size for heading (disabled for 'Attached' layout);
• 'Theme' for heading and content (single input for 'Combined' layout);
• 'Rounded corners' for heading and content (single input for 'Combined' layout);

Examples of generated code:
Default layout:

<h3 class="ui-bar ui-bar-a">Heading</h3>
<div class="ui-body">
    <p>Content</p>
</div>

Combined layout:

<div class="ui-body ui-body-a ui-corner-all">
   <h3>Heading</h3>
   <p>Content</p>
</div>

Attached layout:

<div class="ui-corner-all custom-corners">
  <style type="text/css" scoped="scoped">
     ...
  </style>
  <div class="ui-bar ui-bar-a">
    <h3>Heading</h3>
  </div>
  <div class="ui-body ui-body-a">
    <p>Content</p>
  </div>
</div>