cmake: add an option to control dependencies vendoring

Disable by default, to be used by distributions who care to try and
prefer system-wide libraries when available. It makes sense for us to
keep using vendored libs by default when possible to make it easier for
users to compile, but we should provide appropriate tools for distro to
figure out which dependencies they can share with the rest of the
system.

0 files changed, 0 insertions, 0 deletions