After the recent garrote change, I was inspecting the code to find that
the mob damage formula was somewhat broken. I've fixed this and tweaked
it up a fraction to bring it up to an acceptable level. This change also
means that silver fangs will increase the damage done to denizens, as it
was always meant to.

If you encounter any irregularities with this change, please file it via
the BUG command.

Penned by My hand on the 10th of Glacian, in the year 513 AF.