Large, performance-related commit.

	1. Created separate structs for BED and BEDCOV in order to reduce memory consumption.  Savings of ~30%.
	2. Changed the binning approach to make 16kb bins the most granular.  IntersectBed is now 1/3 faster as a result.
	3. Templated the parsing and reporting functions in bedFile.  Had to move them to the header file to avoid linker complications.
	4. Added CHRPOS as a common type.