Comment 5 for bug 1579219

Based on conversation with Galen on original patch idea, going ahead and making mod_perl a core dependency that's installed on Evergreen side of things, and also making sure to enable perl via the apache mods list.

Pushed to Evergreen master for 2.12.

Holding off on the removal of mod_perl from OpenSRF side for now. We can always choose to remove it in a future release series of OpenSRF. Even if we end up checking to install it in both Evergreen and OpenSRF, we're very safe in making sure that mod_perl is installed and activated either way.