-added an algorithm for rooting trees. It will root the tree at the branch that best balances the subtree lengths (patrsitic distances)
 of the two subtrees defined by this branch.
 example: ./raxmlHPC -f I -t smallTree5 -m GTRCAT -n runID
-refined the TC and IC calculations Salichos and Rokas (2013)
-integrated Andre's patch for generating bootstrap replicates