bug fix
"acknowledgments" lines skipped
content vector builders and models updated
evaluators updated
comments and classes numbers added
null label changed to OTH_UNKNOWN
training samples generator based on documents iterator added
builders updated
unused file deleted
resources moved to test
lowered recall treshold removed
models updated
tests and expected outputs updated
Merge branch 'merged_master' of https://github.com/CeON/CERMINE into merged_master