OPENNLP-684
OPENNLP-685
OPENNLP-686
OPENNLP-691
Added prob support to Span and LinkedSpan. SentenceDetectorME and NameFinderME return Span[] with probs. All tests pass locally. Also made minor javadoc and formatting changes on EntityLinker and TokenNameFinder

git-svn-id: https://svn.apache.org/repos/asf/opennlp/trunk@1594063 13f79535-47bb-0310-9956-ffa450edef68