Initial implementation of DBpedia structured search

DBpedia relations of concept clues are converted to candidate answers,
with LATs matching the property names. Very naive.
answer.FocusGenerator: Dirty fix for unsanitized inputs from DBpedia
LATMatchTyCor: Actually generate AF_TyCorADBpRelation
AnswerScoreLogistic: Retrained with updated model
Merge remote-tracking branch 'origin/dbpans' into dbpans
Merge branch 'dbpans' of github.com:brmson/yodaqa into dbpans