Minor changes

- More descriptive comments useful when doing parallel plan
- Feature to allow color console output (stolen straight from MoveIt!)
It seems to ignore them. However, if I redirect messages to a log file and open that file with an editor, the text will likely not look right. What I meant to say is that you need to detect whether you are printing to a terminal. On Linux and OS X you can use the libc function isatty for that. See also http://stackoverflow.com/questions/18081392/discrimination-between-file-and-console-streams