-some code cleanup
-added andre's patches:
 patch 1: option to compute consensus trees for arbitrary user-specified thresholds > 50%
 patch 2: bug fix in bootstrap re-sampling when a weight file (-a option is used)
-included new options -f G, -f N, -f H and -f W, they do the same thing as their lower-case
 counterparts, but re-optimize the model parameters for all trees in the tree files.
updated version number and date