.external.postag: tweaks
.external.postag: allow empty and arbitrary tokens

Arbitrary tokens: supply a function txtfn to return the text
associated with a token
Ability to align Penn Treebank with RST_DT corpus

Hopefully some of the PTB bits will transfer to the PDTB as well.
Update API docs to reflect new PTB stuff
Remove obsolete text_span second arg
RST_DT: some PTB related features

Penn Treebank properties for the EDU
------------------------------------
[D] ptb_word_first     first PTB word in the EDU
[D] ptb_word_last      last PTB word in the EDU
[D] ptb_pos_tag_first  POS tag for first PTB token in the EDU
[D] ptb_pos_tag_last   POS tag for last PTB token in the EDU
[D] ptb_word_first2    first two PTB words in the EDU
[D] ptb_word_last2     last PTB words in the EDU
[D] ptb_pos_tag_first2 POS tag for first two PTB tokens in the EDU
[D] ptb_pos_tag_last2  POS tag for last two PTB tokens in the EDU

Also:

[D] same_ptb_sentence  if in the same sentence (ptb segmentation)
RST DT clean/tune ptb text

There needs to be a better way to handle this
Avoid another csv parser trap (backslash)

As far as I understand it, the problem is mostly that different
tools in our chain use different escaping conventions for csv.

CSV is probably a silly format to use at the end of the day, but
it's so temptingly compact for feature files.
STAC features: extract separate (e1,e2) (e2,e1)

Previously we working in a non-directional fashion.
Which was silly
STAC: fix subtle parsing-mode bugs

Basically we want to avoid accidentally reparsing the output of
the discourse parser.

In --parsing mode, we don't know what the labels are because we
have presumably live data, so we should read files from the
unannotated stage (and the units stage for dialogue acts), and
filter on unannotated stage for features

A second issue is that dialogue acts were missing from live mode
features because unannotated files do not have authors, but the
dialogue act extracted ones do, so we have to relax the doc
match accordingly
STAC features : fix empty annotator in unannotated
Refactor stac feature extractor with magic keys

Magic keys allow us to define features as standalone functions
with their help text providing descriptions, and feature names
coming from the function itself.
Kill dead code
Fix help text
Use setuptools.find_packages

Why on earth was I resisting this? I seem to recall having this
and then getting rid of it.
Update my email address
Merge branch 'master' of github.com:kowey/educe