Previously used time() which has 1 second precision.
Now use gettimeofday() which has millisecond precision.

	1. Reset BED.strand to be string instead of char in the interest of generality.
	2. Fixed bug in genomeCoverageBed where NULL entries where genome summaries were err. reported with -bga.
	3. Fixed bug in closestBed where NULL entries were err. reported when BED > 6.
	4. Standardized the Open, Get, Close idiom per improvements from Gordon Assaf.
	5. Add "split" logic to bamToBed.