added DEF dependency for WikiUtil
added input format that reads from pignlproc output

output of nerd-stats.pig can be indexed if named as .tsv file
fixed indexer for non-sorted input

- uses IndexReader to fetch existing document and change only new fields
- sorted input is still faster because all consecutively read data is collected in memory
- also put PignlprocInputFormat in place
moved util.DBpedia2Lucene to inputformat.DBpediaNTriplesInputFormat
update pom dependencies

- Lucene 3.6.2
- NxParser 1.2.3
- bump own version to 3.1
do not use default_index_path any more

- explicitly give index directory to Server class
- updated README.md
creation of labels for schema.org classes

+ call methods with parantheses
+ other comment
+ whitespace
major changes in indexing

Indexer does not rely on sorted input any more.
- Reads data points to a map,
- merges with Documents in index,
- and then commits.

New trait InputFormat for reading from a source and emitting triples of data points.
Implementations:
- DBpediaNTriplesInputFormat (for indexing DBpedia datasets like before)
- PignlprocTSVInputFormat:
  Reads TSV that is produced by nerd-stats.pig script from dbpedia-spotlight/pignlproc
  project. This script gets surface forms from Wikipedia and scores them.
  There is a threshold for the score p(sf | uri) that captures how common a surface
  form is for a URI.
  (see also commit ac24a8866c7ba65201f123f9b7142d7bee7b130a)
update README to reflect new indexing pipeline
added Apache 2.0 license
Merge pull request #4 from maxjakob/newIndexing

New indexing

-    index data coming from pignlproc nerd-stats.pig that provides surface forms and scores
-    Indexer does not assume sorted input any more, but it speeds up the process
-    default_index_path is not used any more (was a weird idea to begin with) give the index dir directly to the Server
-    DEF dependency because we need WikiUtil and don't want to duplicate any more

IMPORTANT: added Apache License 2.0 file.