[CMake] Ignore install()

[Stefan Schindler]

Hey guys,

I wonder if it's possible to ignore install() commands in projects that
are being built using add_subdirectory().

I've got a project that builds external libraries and links statically
to them, so there's no need to install them in the final step.

A workaround is to remove the files after installing, but I'd rather go
with a "cleaner" solution.

Greetings,
Stefan.