signup 5.x-2.0

Initial official release of the 5.x-2.* new feature series. Enhancements since 5.x-1.0:

• #106808: Initial views integration. At this time, all the fields from all signup-related database tables are exported, and there are a handful of filters, sorts, and arguments. There are no default views yet.
• #106891 : Signup broadcast functionality -- sufficiently privileged users now have the ability to send an email directly to all the users who signed up for a given node on the site by using the "signup-broadcast" tab.
• #79332 : Cleaned up the user interface for the signup administration overview page. It used to be misusing tabs as a way to filter what signup status (open, closed, or all) to view. Now there is a drop-down selector where the administrator can choose what signup status to filter the page with.
• #134609 : Added an advanced setting to control if the signup form is collapsed or expanded by default.