[afew] announcing afew, an universal tagging solution with some fancy features

[Patrick Totzke]

Hi Justus,

I have just tried your script and have some questions/remarks about it:

* mkdir -p ~/.config/afew ~/.local/share/afew/categories
  As far as I can see, this is not needed if one doesn't use ClassifyingFilter,
  so its OK not to do this directly from the setup.py somehow.
  But it would be nice if a first run uf `afew --learn` would
  create these (or die gracefully instead of raising the afew.DBACL.BackendError).

* if you renamed the README & co to include the suffix ".md" github would nicely
  render them on the project page.

* I need some more info on how the config works: first, the order in which the
  sections are defined specifies the filter-pipeline yes?
  Secondly, what exactly is a "filter object" in the config?
  Specifically, what do these 3 lines do:
  https://github.com/teythoon/afew/blob/master/docs/tag_filters#L39

* this is surely a user error: I cannot use afew for initial tagging as expected:
  I installed as stated in the README,
  trained some of my existing tags and called `afew --update-reference` and `afew --update`.
  The test with `afew --classify -- ..` works nicely.
  Now I tagges all my mails with is:new, and called `afew --tag --new`.
  This returns immediately without output and all my messages are still tagged new.
  Also, -vv does not result in any output..
  ideas?

Looking forward to replacing my sort script with this.
Thanks,
/p