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/ja_JP.dt-eucJP/msg/MotifApp.msg

@@ -1,27 +1,27 @@
-$
+$ 
 $   COMPONENT_NAME: desktop
-$
+$ 
 $   FUNCTIONS: none
-$
+$ 
 $   ORIGINS: 27,118,119,120,121
-$
+$ 
 $   This module contains IBM CONFIDENTIAL code. -- (IBM
 $   Confidential Restricted when combined with the aggregated
 $   modules for this product)
 $   OBJECT CODE ONLY SOURCE MATERIALS
-$
+$ 
 $   (C) COPYRIGHT International Business Machines Corp. 1995
 $   All Rights Reserved
 $   US Government Users Restricted Rights - Use, duplication or
 $   disclosure restricted by GSA ADP Schedule Contract with IBM Corp.
-$
-$
+$ 
+$ 
 $ +SNOTICE
-$
+$ 
 $  $XConsortium: MotifApp.msg /main/5 1996/10/16 03:13:05 cde-hit $
-$
+$ 
 $  RESTRICTED CONFIDENTIAL INFORMATION:
-$
+$ 
 $  The information in this document is subject to special
 $  restrictions in a confidential disclosure agreement between
 $  HP, IBM, Sun, USL, SCO and Univel.  Do not distribute this
@@ -29,11 +29,11 @@ $  document outside HP, IBM, Sun, USL, SCO, or Univel without
 $  Sun's specific written approval.  This document and all copies
 $  and derivative works thereof must be returned or destroyed at
 $  Sun's request.
-$
+$ 
 $  Copyright 1993 Sun Microsystems, Inc.  All rights reserved.
-$
+$ 
 $ +ENOTICE
-$
+$ 
 
 $quote "