Allow themes to provide default pages so that Panels Everywhere enabled themes can provide layout variants for the site template.

Introduce 'export callback' to individual fields in export.inc. Add some documentation to export.html -- much of it borrowed from stella!

#596450 by Scott Reynolds: Provide an ajax command response to reset the modal to the loading state.

#589342: Introduce page_manager_get_current_page() to get information about the current page manager page.

Add cleanstring.inc tool to facilitate more pathauto-like functionality without necessarily using aliasing.

#545540 by Roger López: Add 5 page elements as available panes for using Panels as your primary page layout: breadcrumb, page title, messages, tabs and help box.