more artifact tracking

This should have been broken up into multiple pieces but they're
all lumped together.  I did ultimately throw away a fourth change.

Implement artiexist[].bones and artiexist[].rndm artifact creation
tracking bits that were added recently.  Doesn't need to increment
EDITLEVEL this time.

Add a new wizard mode feature:  if you use `a to show discovered
artifacts, it will prompt about whether to show the tracking bits
for all artifacts instead.  If not using menustyle traditional,
you need at least one artifact to have been discovered in order to
have 'a' choice available when selecting what class of discovered
objects to show for the '`' command.

artifact_gift(), aritfact_wish(), and so forth return a value that
none of the existing callers use, so cast their calls to (void).

src/bones.c

@@ -71,6 +71,7 @@ resetobjs(struct obj *ochain, boolean restore)
                         free_oname(otmp);
                 } else {
                     artifact_exists(otmp, safe_oname(otmp), TRUE, FALSE);
+                    (void) artifact_bones(otmp, TRUE);
                 }
             } else if (has_oname(otmp)) {
                 sanitize_name(ONAME(otmp));