FIX: quit after using --help startup option

fixes: Oldes/Rebol-issues#2430

src/mezz/mezz-help.reb

@@ -382,7 +382,7 @@ import module [
   
       ^[[1;32m--args data^[[m      Explicit arguments to script (quoted)
       ^[[1;32m--do expr^[[m        Evaluate expression (quoted)
-      ^[[1;32m--help (-?)^[[m      Display this usage information
+      ^[[1;32m--help (-?)^[[m      Display this usage information (then quit)
       ^[[1;32m--script file^[[m    Explicit script filename
       ^[[1;32m--version tuple^[[m  Script must be this version or greater
   

src/mezz/sys-start.reb

@@ -90,12 +90,17 @@ start: func [
 		do bind-lib boot-mezz
 		boot-mezz: 'done
 
+		;loud-print "Init protocols..."
 		foreach [spec body] boot-prot [module spec body]
 		;do bind-lib boot-prot
 		boot-prot: 'done
 
 		;-- User is requesting usage info:
-		if flags/help [lib/usage quiet: true]
+		if flags/help [
+			lib/usage
+			unless flags/halt [quit/now]
+			quiet: true
+		]
 
 		;-- Print fancy banner (created by mezz plus):
 		if any [