The goal is to finish project groups:
- Search to be extended with a scope 'all files in project group' if a project group is active.
- A way so 'Ctrl-F9' will compile the current target (be that project or package) in the active project group.
This implies that
a) one can mark the project group as 'active'
b) one can mark a project in the project group as 'active'.
Alternatively:
Make project groups the basis of the IDE instead of a project.
A bounty of 200 EUR was offered for this functionality.