<Mon> suddenly appears! vs ^G

For ^G, throttle the monster creation feedback.  Don't say "suddenly"
and don't exclaim the message, just say "<Mon> appears."  Also, use
Norep() so creating lots of similar monsters at once only gives a few
messages (just one unless varied by "next to you" vs "nearby" vs no
qualifier for farther away).  And for mimics created as objects or
furniture, report the sudden appearance of new object or furniture.

include/hack.h

@@ -296,6 +296,7 @@ typedef struct sortloot_item Loot;
 #define GP_ALLOW_XY 0x080000L /* [actually used by enexto() to decide whether
                                * to make an extra call to goodpos()]        */
 #define GP_ALLOW_U  0x100000L /* don't reject hero's location */
+#define MM_NOEXCLAM 0x200000L /* more sedate "<mon> appears." mesg for ^G */
 
 /* flags for make_corpse() and mkcorpstat(); 0..7 are recorded in obj->spe */
 #define CORPSTAT_NONE     0x00