Major update to the build system, the database schema, and functionality.

[NEW] Switching build system from ant to maven.
[NEW] Integrated web service, call AIDA using HTTP calls (check the
documentation for details).
[NEW] Database additons: entities have types (thanks to YAGO) and image
urls (thanks to DBpedia).
[NEW] Filtering candidate entities by semantic (YAGO) types.
[NEW] Mention-entity scores can be changed to approximate confidence by
simple normalization.

[CHANGE] Normalization for keyphrase similarity computation is now
document-wise, not global.
[CHANGE] CommandLineDisambiguator uses different syntax for parameters
(unix style).
[CHANGE] JSON output format has been adjusted, now has different modes.
Also keeps less information inside the mentions. All entities data is
stored in per-document entityMetadata field.
[CHANGE] Database schema has been upgraded to v5.

[FIX] Restricting keyphrases also restricts keywords (fast mode).
[FIX] CoNLLReader works with public dataset.
[FIX] No more exceptions for documents with 0 mentions (thanks to
Nadine Steinmetz for fixing this).