1. Fixed yet another bug in the parsing of "track" or "browser" lines.  Sigh...
2. Change the "score" column (i.e. column 5) to b stored as a string.  While this deviates
   from the UCSC convention, it allows significantly more information to be packed into the column.

	1. Added strandedness to relevant programs (e.g. intersectBed, mergeBed, etc.)
	2. Moved reportBed and reportBedRange to bedFile.cpp to clean up code
	3. Sped up file parsing.  Added lineFileUtilities.cpp
	4. Added peIntersectBed

	1.  Added subtractBed.
		A. Fixed bug that prevented "split" overlaps from being reported.
		B. Prevented A from being reported if >=1 feature in B completely spans it.
	2.  Added linksBed.
	3.  Added the ability to define separate windows for upstream and downstream to windowBed.