buglist entry: hobbits and elven mithril armour

<Someone> wrote: "Also, hobbits can't wear armour,
at least, you can't wear armour when polymorphed into a hobbit, even
though hobbits do tend to be carrying elven mithril-coats.
It's tempting to suggest adding an explicit exception in
sliparm() for elven mithril just to keep the Tolkienness."

- added a general routine for adding race-based /object
combination exceptions.
- hobbits can wear elven mithril-coats

doc/fixes34.1

@@ -404,4 +404,4 @@ fire traps are particularly bad for paper and straw golems
 cream pies can be 'a'pplied to cause direct temporary blindness
 eating newt corpse or tin of same can boost magical energy (Malcolm Ryan)
 applying a eucalyptus leaf produces a whistle effect (Malcolm Ryan)
-
+hobbits can wear elven mithril-coats