message catalogs: fix comment lines, also remove linux hack in merge.c

According to the spec, blank lines in message catalogs or lines
beginning with '$ ' are valid comments.

However, there were many cases where lines in the message catalogs
contained just a single '$', without the required space after it.

Under linux, this caused 126766 error lines (in my builds) of the
form:

... unknown directive `': line ignored

This also causes gencat to exit with a non-0 exit code.  Even though
gencat says it ignores the line, it really doesn't.

An early porting change to programs/localized/util/merge.c was made to
ignore this return value on linux.  This hack has now been removed.

Build logs are a lot smaller and cleaner now.

cde/programs/localized/es_ES.ISO8859-1/msg/dtconfig.msg

@@ -119,27 +119,27 @@ $
 23 "la actualización de la acción de impresora se ha completado"
 
 24 "Uso:  "
-$
+$ 
 25 " %s -inetd    (daemons inetd.conf /usr/dt)"
 26 " %s -inetd.ow (daemons inetd.conf /usr/openwin)"
-$
+$ 
 $	In above messages 25 and 26, only translate words between
 $	left "(" and right ").
-$
+$ 
 27 "La próxima inicialización del sistema se ejecutará desde /usr/dt/bin"
-$
+$ 
 28 "    rpc.ttdbserverd         (ToolTalk)"
 29 "    rpc.cmsd                (Gestor del calendario)"
 30 "    dtspcd                  (Control de subprocesos)"
-$
+$ 
 $  Keep column allignment on messages 28 thru 30.  
 $  Only translate what's beteen ( )'s
-$
+$ 
 31 "La próxima inicialización del sistema se ejecutará desde /usr/openwin/bin"
-$
+$ 
 32 "    rpc.ttdbserverd         (ToolTalk)"
 33 "    rpc.cmsd                (Gestor del calendario)"
-$
+$ 
 $  Keep column allignment on messages 32 thru 33.  
 $  Only translate what's beteen ( )'s
-$
+$