VDOT calculator and Jack Daniels Long Runs

Major update to VDOT calculator. I've added generation of the long runs required for two of the Jack Daniel's Marathon plans, Plan A and the Elite plan. These plans are quite tricky to work out by hand, especially the elite plan, so this should make life easier for anyone who wants to evaluate or use the Jack Daniel's system. In addition I've added more support for metric units and added the 3200M pace for the FIRST system. Check it out and let me know what you think http://fellrnr.com/wiki/VDOT_Calculator