Organize includes into include groups

[alaguilles]

This doesn't seem possible with the available parameters at this point.

[pgalbavy-itrs]

Three requirements to do this:

1. Templates that understand groups - this might be as easy as having a "default" group so there is no distinction between includes in groups and those not (ignoring instance.setup.xml for now)
2. The command line format is getting more and more complex - currently for includes it's -I 100:/path/to/include - how do we indicate group name as an option?
3. How to store this in the instance config and be backward compatible

The same questions may also apply to adding multiple managed entities to SAN templates, and the requirement for subsequent attributes, types, variables needing to live "under" specific entities.

Ideas welcome, and I will think more...