Added ability to provide description for guards and actions to improve
generated documentation.
Remove default parameter for Holder classes, since Code Analysis doesn't like it.  Also add XML comment for new description parameter where required.
Add unit test for the new description parameter.
Remove default parameters from IFactory and add passing null to StateBuilder.g.cs
Improve description for parameterized actions.  Now the parameter provided for the action will be logged as well.
Update unit tests to pass now that I have XUnit installed correctly.
Update State Machine Report tests to pass now that 'none' is reported in some cases