data.headers

1. Why?

  before: three Haraka plugins to do header tests, and likely to sprout more
  after: one plugin, one .ini file. Edit .ini to add/remove headers to/from the lists.

  before: all RFC 5322 header checks, or none, or edit source code
  after: user configurable, when header checks prove desirable/troublesome

  new feature: sanity testing of Date field (if present).
  an obvious place to put future header tests, w/o littering the plugins dir

2. How - In the interests of not changing how existing plugins work, I created a 'new' one, combining the functionality of the old ones. That way, when someone upgrades, I presume the old plugins will remain locally installed, and will continue to work exactly the same, until they read UPGRADE, and update their local config/plugins file. 

I expect there's some other preferred mechanism for making a change like this, of which I'm about to become familiar. :-)

Happy Holidays!