Minor typos
Enhancements to the getSomeAcceptedWord interface

* PathVisitor added to languages.hpp header
* WFA support for path_summary_tarjan (not yet working with FWPDS)
* getSomeAcceptedWord can pass back the witness for reinterpretation
* Previous interface maintained
Merge branch 'master' of github.com:WaliDev/WALi-OpenNWA
Add getLength() method to witnesses

And sync with getSomeAcceptedWord debugging
Merge branch 'master' of jamweaver:crash/jam/wali
Merge branch 'master' of jamweaver:crash/jam/wali
Add min_length field to witnesses.

The value is calculated at construction, except for WitnessCombine, which examines each child as it's added to find the minimum.
CalculatingVisitor just has a small name change.
Improvements in accepted word search

ShortWitnessVisitor extracts the shortest single-path witness from a
more complex witness by pruning the longer child of combines.
PathVisitor can then build a nested word from that path.
PathVisitor.cpp moved to Source/opennwa/query and it now has its own
header file.
Various improvements to the getSomeAcceptedWord framework.
Merge branch 'master' of git://github.com/WaliDev/WALi-OpenNWA
Implemented WitnessLengthWorklist

Heuristically propagates shorter witnesses during poststar
Merge branch 'master' of git://github.com/WaliDev/WALi-OpenNWA

Conflicts (resolved):
	Source/wali/graph/RegExp.cpp
	Source/wali/wfa/WFA.hpp
Merge branch 'master' of git://github.com/WaliDev/WALi-OpenNWA
KeyedSemElemSet: create PositionKey class

This is a "SemElem" (but not really) that will often be useful (hopefully) as a key type for the future KeyedSemElemSet class.

Tests included.
KeyedSemElemSet: my PositionKey class needs a one() function after all
KeyedSemElemSet: add dummy impls of functions and comment
KeyedSemElemSet: change tests to use refptrs instead of values
KeyedSemElemSet: make it store a backing set, add a couple accessors
KeyedSemElemSet: add one() and zero() functions

The one() function includes the ability to pass an empty set to the constructor and still be able to construct a one (but this bit isn't tested)
KeyedSemElemSet: add extend function (no duplicates allowed yet)
KeyedSemElemSet: implement the equal() function