refactor tabs to spaces
Add name field for priority level
Make the fromString and fromInteger method return null  instead if it fails to find a match
Allow priority level to be set by colour. Also factored out the createMessage method into a common functionality that can be used across different classes.
Add tests
apply slap
Clean up
more clean up
Allow setting of default priority level, as well as priority by first letter (d, g, o, r)
Merge remote-tracking branch 'origin/pn-priority-colour'