initial refactor
Removed some unneeded functions
Began moving code into class structure (again)
Bug fix : is and == are not equivalent (for some reason)
Run and step functions are independent
Added run generator
Added correct measure of number of escaping photons
altered fetch_data to customised
added ctags
Bug Fix : verbosity control no longer used
added phi confinement to segment reflection
Added optional critical angle and catches to ensure the function still runs
Merge branch 'master' of github.com:marksbrown/photontracing