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/allmain.c

@@ -812,7 +812,7 @@ interrupt_multi(const char *msg)
 {
     if (g.multi > 0 && !g.context.travel && !g.context.run) {
         nomul(0);
-        if (flags.verbose && msg)
+        if (Verbose(0,interrupt_multi) && msg)
             Norep("%s", msg);
     }
 }