Rewrote complementBed to use a slower but much simpler approach. This resolves several bugs with the previous logic.

	1. Updated the mergeBed documentation to describe the -names option which allows one to report the names of the
	features that were merged (separated by semicolons).

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. When using stdin, the "inspan" annd "outspan" modes were not working.
	   Simple bug in the if statement...copy and paste error.