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/imports/motif/localized/fr_FR.ISO8859-1/msg/Mrm.msg

@@ -1,5 +1,5 @@
 $ $XConsortium: Mrm.msg /main/3 1996/10/19 15:28:17 rws $
-$
+$ 
 $  @OSF_COPYRIGHT@
 $  COPYRIGHT NOTICE
 $  Copyright (c) 1990, 1991, 1992, 1993 Open Software Foundation, Inc.
@@ -13,7 +13,7 @@ $ (c) Copyright 1996 Sun Microsystems, Inc.
 $ (c) Copyright 1996 Novell, Inc. 
 $ (c) Copyright 1996 FUJITSU LIMITED.
 $ (c) Copyright 1996 Hitachi.
-$
+$ 
 
 $ This message catalog contains messages issued by Motif Mrm library.
 $ Consult X-Window systems, OSF/MOTIF Programmer's Guide and OSF/MOTIF

cde/imports/motif/localized/fr_FR.ISO8859-1/msg/Xm.msg

@@ -1,11 +1,11 @@
 $ $XConsortium: Xm.msg /main/8 1996/10/19 15:28:23 rws $
-$
+$ 
 $  @OSF_COPYRIGHT@
 $  COPYRIGHT NOTICE
 $  Copyright (c) 1990, 1991, 1992, 1993 Open Software Foundation, Inc.
 $  ALL RIGHTS RESERVED (MOTIF). See the file named COPYRIGHT.MOTIF for
 $  the full copyright text.
-$
+$ 
 
 $ This message catalog contains messages issued by Motif toolkit library.
 $ Consult X-Window systems, OSF/MOTIF Programmer's Guide and OSF/MOTIF