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/attrib.c

@@ -170,7 +170,7 @@ adjattrib(
         abonflg = (ABON(ndx) > 0);
     }
     if (ACURR(ndx) == old_acurr) {
-        if (msgflg == 0 && flags.verbose) {
+        if (msgflg == 0 && Verbose(0, adjattrib)) {
             if (ABASE(ndx) == old_abase && AMAX(ndx) == old_amax) {
                 pline("You're %s as %s as you can get.",
                       abonflg ? "currently" : "already", attrstr);