Slackware package upgrades
Today I've had a look at the Slackware security advisories, and decided to upgrade libpng and git.
My doubt is, should I install the new package without removing the old one, or should I remove the old one first?
For example, I've installed the new libpng, now I have both libpng-1.2.27 and 1.2.35.
I'm not sure if I should uninstall the old version, since some programs might be using its shared library. On the other hand, should I worry about disk space usage by old packages?