Many changes.
Cache mention term vector and make features lazy vals.
Fix 10 to 1 neg to pos mention pair training, update to non-global kbpqueryhelper.
Factor out KBPQuery global mutable state into KBPQueryHelper class
Remove global mutable state and update to use KBPQueryHelper
Make KBPQueryHelper fields non-optional
Restore old linkclassifier threshold.
Merge branch 'master' into classifier

Conflicts:
	src/main/scala/edu/knowitall/tac2013/entitylinking/KBPQuery.scala
	src/main/scala/edu/knowitall/tac2013/entitylinking/RunKBPEntityLinkerSystem.scala
	src/main/scala/edu/knowitall/tac2013/entitylinking/classifier/MentionPairTrainingData.scala
	src/main/scala/edu/knowitall/tac2013/entitylinking/classifier/SportsSenseTrainingData.scala
Merge pull request #33 from rbart/classifier

Remove global mutable state