optionally convert input files from c(parent, child) data frame to the input taken by SRCgrob. The goal is to support human readable format without introducing too many changes to the internal workings of CEV. It will also automatically save plots to a file.
saves output file: make a save.plot function and automatically save to file when filename is specified (BPG convention)
Make plotting function more informative and maybe match BPG naming schemed (e.g.create.tree.plot, create.phylogenetic.tree)
Add a wrapper function that does the following: