0.1 -> 0.2 
    Added function for power for F2 intercross
0.2 -> 0.3
    Corrected function for discount factor for F2 intercross.
0.3 -> 0.31
    Corrected F2 power function and detectable effects function.
    It was not doing the right thing for non-zero marker intervals.
    Analytical error.
0.31 -> 0.32
     Changed the dominance coding to be consistent with Karl's R/qtl.
0.32 -> 0.80
     Major changes; too many to document.  Changed syntax of many
     commands.  Deleted the simulation commands.  Made the whole
     package more practical.
0.80 -> 0.81
     More complete documentation.  Corrected bug in powercalc
     wrapper function.
0.81 -> 0.85
     - Changed alpha to sel.frac in all arguments to minimize confusion
       between alpha, the level of a test, and the selection fraction.
     - Changed the name of the function "optalpha" to "optselection".
     - The functions "powercalc", "samplesize", and "detectable"
       now accept the arguments bio.var, gen.var, and bio.reps directly; 
       it is not necessary to call "error.var" any more.
     - The functions "powercalc", "samplesize", and "detectable"
       now output the percent variance explained also.
     - New function called "prop.var" which calculates the proportion
       of variance explained by a locus given the cross type, effect,
       and error variance.