dia to sml: transform model comments when marker is found
sml: add implementation specific parameters to packages
dia to sml: remove redundant packages by ID in context

Best to perform a double look-up rather than duplicate packages.
dia to sml: add transformer support for comments at the package level

- add package inside of package scenario to the comments model
cpp: add new aspect type for namespace documentation
cpp: initial stab at adding a namespace documentation formatter
cpp: start generating namespace documentation view models