Fixes#240
Monster versus monster (melee and throwing) didn't handle shades
(need silver or blessed weapon to take damage) or silver feedback
(extra info when silver-haters are hit).
I did a lot of test, revise, re-test but didn't always re-test
everything that had previously been tested, so bugs that I thought
were quashed might have crept in.
Now if a missile weapon "passes harmlessly through the shade" it
will continue on and maybe hit something else. (Regular misses
still stop at the missed target.)
A couple of minor ball&chain changes accidentally got included.
f3a923d647