[CMake] Launching a script after user picks components in component-based installers

[Mathias Gaunard]

With a component-based installer such as NSIS, the user can choose the 
components that he wants to install.

I would need to launch a script (just launching an external program 
would do) after this, telling me where the application was installed, so 
that I can perform additional actions depending on which components were 
installed or so I can autoconfigure the application according to the 
system settings.

Does CMake/CPack allow to do something like this?

I see that RPM appears to allow to specify a shell script for post 
install, but I'd like to have something that works for all 
component-based CPack generators, and all operating systems.