TODO: discussion and rewrite of existing hide logic
To convert a banner to use this mixin,
Go to the banner edit page.
Remove the BannerShowHideCount template from the banner content, make a note of your parameter values.
Check the BannerShowHideCount mixin and save the banner.
Banner message fields should appear for the four parameters. Enter the old values into these fields and save again. Note that the parameter names have been changed to protect your sanity.