Shortcode for BSP announcement signups

[imrehg]

Create a shortcode (or plugin) for BSP signups, so to better organize things reduce the number of code that can go wrong.

Ideas:

• plug in directly to MailChimp and get a list / groups to display.
• add option to autoselect fields
• option to organize the order of the fields, and header text

(or use something like the WP Mailchimp Plugin if possible.