Make paralysis intefere with seduction attempts

tinklebear on IRC noticed that a hero paralyzed by a floating eye was
still "charmed" and capable of "removing her armor" as part of a nymph's
theft attack.  The same thing was true of foocubus seduction: a
paralyzed hero was still able to respond to the questions about whether
particular pieces of armor should be removed (and also do whatever else
may be involved in a successful attack...).

I think paralysis should prevent both those things.  Nymph theft will
still work, unless she needs the hero's active cooperation in removing a
bulky piece of armor.  Foocubus attacks will be prevented entirely by
paralysis, making it interfere like unconsciousness already does.

Apply a similar constraint to hero vs monster seduction, as well.

include/extern.h

@@ -2680,6 +2680,7 @@ extern int num_spells(void);
 extern long somegold(long);
 extern void stealgold(struct monst *);
 extern void thiefdead(void);
+extern boolean unresponsive(void);
 extern void remove_worn_item(struct obj *, boolean);
 extern int steal(struct monst *, char *);
 extern int mpickobj(struct monst *, struct obj *);