Issue #2292897 by dieuwe: Completed views handler for showing bounce rates. There is still work to do on testing an improving the basic functionality.

Issue #2292897 by dieuwe: Bounce and unsubscribe rates. Groundwork for views integraion of counting unsubscribes between newsletter sends.

Issue #1750906 by stijnd: Add HTML email as an install requirement. Warning messages set per newsletter where the category format has not been set to html.

Issue #2295439 by dieuwe: Delete/archive newsletter statistics. Basic views support for new archived fields. More work needs to be done here.

Issue #2295439, by dieuwe: Delete/archive newsletter statistics. Individual url click counts should now be archived too.

Foundations for better views integration. Moved simplenews_statistics record creation to hook_node_insert(). Added simplenews_statistics_is_archived() function.

Cron can now archive newsletters. This has no functional implications
yet.

Updated schema to accommodate archiving and aggregating open and click
counts.

Implemented hook_cron and added an option for the length of days to keep
open and click records. After this time records are deleted.

Added function to count the number of unsubscribes for a newsletter
category.

Added a notice about HTML email to the 'requirements' section of the
README.txt.

style hashing option for the encoder.

system so that it handles any id instead of duplicating hooks on a per
id basis.

check for valid snid to open function.

an option to enable or disable the tracking of test send opens and
clicks.

overview page implementation with a view.

the content simplenews tab, similar to the one found in the D6 version
of this module.

supports unique clicks and the CTR supports decimal precision.

uses unique open count and supports decimal precision.

show unique count and open rate.

Also made the 'sent count' that simplenews provides more obvious to find by changing the title and description with hook_views_data_alter().

various calculations. Reintroduced the {simplenews_statistics} db table.

replacement.

subscriber record.

terminates.

handled. We now rely on a single variable for link tracking, and two for open tracking.