[CMake] automatic install of targets

[Jan Wurster]

Hi everyone,

>  Since dependency handling seemingly has been improved in cmake 2.6.2,

> the probably correct behaviour now means that a project that gets 
> added by add_subdirectory now is installed while it's not actually 
> built yet, leading to a post-build error. This is especially true for 
> projects that have a dependency to their 'top' target - it's a hen vs 
> eggs problem after all.

 After evaluating a few ideas I think I'll be able to fix this using
COMPONENT Specifications on each target. That way I can define that only
targets definitely built get installed, therefore only having hens (or
eggs).

 Just to fill up on the issue - best regards,
-.jan.-