I softened the "you are hit so hard you fly off your horse making a Wilhelm
scream" code a tad. Mount resists will now affect the chance, however, they
are not the pivotal factor. A 100% physress mount will still throw you on
physical hits, but the hit has to be stronger to do that. Also, mounts are now
less likely to throw you if you have a history of riding that same mount (the
"owned" mount tune in action, now that it exists).
Changes take place at reboot or stable/unstabling.