Dev

Hi,

Fixed a small bug in the definition of the --gendots argument which meant that args.gendots was populated with "dots" even if the user did not specify '-gd' at all. This meant that the program essentially *always* generated the dot files and never did any of the other commands. Also included are a couple of small tidy edits in pepa_model and I added a Bunch pattern to utils. I'm not actually using this on this branch yet, but it can be useful.

allan