OPENNLP-699
OPENNLP-684
Moved MarkableFileInputStreamFactory and MarkableFileInputStream classes to utils. This prompted a minor change to imports in CmdLineUtil
Removed setter for double prob from Span, and added additional constructors to support spans with probs while preserving immutable. Changed the SentenceDetectorMe and NameFinderME to use the new constructors rather than the setter.

All unit tests pass.

git-svn-id: https://svn.apache.org/repos/asf/opennlp/trunk@1596320 13f79535-47bb-0310-9956-ffa450edef68