ISIS-284: updating archetype generation stuff so that the isis profile is not active in the examples but is active for (applications generated from) the archetypes.
ISIS-284: refactored isis-maven-plugin, factoring out IsisMojoAbstract superclass to remove boilerplate in future mojos.
ISIS-928: minor incidental changes to the todoapp (additional tests)
ISIS-284: renaming of mojo classes to better capture intent (IsisRunnable -> MetaModelProcessor, IsisMojoReporter -> MetaModelProcessor.Context).

Also add the MavenProject into the MetaModelValidator.Context interface, and make private in IsisMojoAbstract.  That way all the stuff that the subclasses (eg IsisMojoValidate) needs is available in the MetaModelProcessor.Context API)
ISIS-284: tiny incidental fix to one of the metamodel validator errors.

(to test the valdator have been renaming ToDoItem#hideDueBy to ToDoItem#hideXDueBy, which triggers this error.   Felt the wording could be improved).
ISIS-284: change the todoapp and simpleapp's "isis" profile to be called "isis-validate".
ISIS-284: use injected @Parameter for configuration rather than reading directly.
ISIS-982: changing the names of the generated war files for simpleapp and todoapp.
ISIS-284: started improving script to generate archetypes

... so the isis-validate profile would be active by default.  Not there yet, though, hence commented out the new stuff
ISIS-928: recreating simpleapp archetype
ISIS-928: recreating todoapp archetype