Issue #2074895 by joachim: creating an account as an admin gives me a 'You have unsubscribed' message

Issue #2062155 by joachim: docs and code disagree on $account param in mailchimp_lists_get_available_lists()

Issue #2147987 by pcoucke, MegaChriz, ndewhurst: Double opt-in is always enabled for batch subscribes

Issue #2302079 by hansrossel: Fixed all users of a role being subscribed when list is not a required list.

These fields are not needed and removing them prevents export conflicts
when meaning data has not been changed.

This led to a recursion memory leak. Also changed all usages of
MailchimpList::label to MailchimpList::label().

#2048755 by levelos: When saving a new list, instantiate it as a MailchimpList class rather than stdClass.

Causing a fatal error when creating new lists since
mailchimp_lists_save() is expecting a MailchimpList object.

Create a MailchimpLists class and move the entity CRUD API calls back into the mailchimp_lists.module file.

Adding group default checkbox to list settings to auto-check group options on registration forms. Address issue #1452330.

Issue 1936352: rules condition fails to display mail variable. Altered rule data type to be * since the 'mail' filter does not exist.

Removing array settings from filter options API documentation: they technically work but not in a usable way.