Support for extracting lexicon from text
Simplify the lexicon-in-text representation
Add support for: pndef_sg, pndef_pl, adj_tr
DRS->OWL: improve handling of toplevel DRS

The improvements are:

  - more DRSs supported
  - less anonymous variables generated,
    except for one type of sentences ('a man is a human.') which now looks more complex in OWL than before
  - better error messages (in a few cases)
  - cleaner code
DRS->OWL: fix in the new handling of toplevel DRS
Replace StringBuffer with StringBuilder
Add more detailed tests.
Launch server before executing tests
Avoid using deprecated HTTP client intferface. Don't add uri parameter to request if none supplied.
Start server before running tests.
Add slf4j and dependencies
Add exponentiation symbol ^

Does not work everywhere yet and is currently
on the same binding level as * and /, which is wrong.
^ has now higher priority than * and /

(Note that ^ is left-assoc, which might be confusing.)
ace_niceace: remove ^ only if it starts token list
Add Makefile to help with some frequent tasks
Merge pull request #12 from Attempto/exponentiation

Exponentiation
Update tests
Merge remote-tracking branch 'upstream/master'
OWLFSSPP format: declare 'ace' IRI abbreviation

This is obviously required to be able to load OWLFSSPP-ontologies
derived from 'there are ...' with OWL-API.
Fix bug: Operator symbols not shown in "simplified syntax trees"