granular verbose message suppression mechanics

Switch to using a macro invocation Verbos(n, s) in place of the
flags.verbose checks.

Provide the mechanics for individual suppression of any of the
existing messages that were considered verbose.

Mechanics only - this code update does not provide any means of
setting the suppression bits.

iflags.verbose = 0
is still a master suppression of all the verbose messages.

iflags.verbose = 1
turns on the verbose messages only for those whose suppression
bit is 0 (not set).

src/dothrow.c

@@ -1301,7 +1301,7 @@ toss_up(struct obj *obj, boolean hitsroof)
 
             /* helmet definitely protects you when it blocks petrification */
             } else if (!petrifier) {
-                if (flags.verbose)
+                if (Verbose(0, toss_up))
                     Your("%s does not protect you.", helm_simple_name(uarmh));
             }
             /* stone missile against hero in xorn form would have been