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/zh_CN.dt-eucCN/msg/dt.msg

@@ -27,32 +27,32 @@ $ *****************************************************************************
 $ *************************************<+>*************************************
 
 $ *****************************************************************************
-$
+$ 
 $ ***** NOTE FOR MESSAGE CATALOG TRANSLATORS *****
 $ 
 $ There may be three types of messages in this file:
-$
+$ 
 $  1. Messages that appear in dialogs or are displayed to the user.
-$
+$ 
 $     These messages are the default and they should ALL BE LOCALIZED.
 $     Note that these messages do NOT have any identification (see the
 $     comments for type 2 and 3 below).
-$
+$ 
 $  2. Messages that only appear in the DT error log file ($HOME/.dt/errorlog).
-$
+$ 
 $     The localization of these messages is OPTIONAL.  These messages are
 $     identified by the following:
-$
+$ 
 $  MESSAGES xx-yy IN SET zz WILL ONLY APPEAR IN THE DT ERRORLOG FILE
-$
+$ 
 $  3. Messages that should not be localized.  
-$
+$ 
 $     These messages are identified by the following:
-$
+$ 
 $  DO NOT TRANSLATE or CHANGE or LOCALIZE MESSAGES xx-yy from set zz
-$
+$ 
 $ ***** END (NOTE FOR MESSAGE CATALOG TRANSLATORS) *****
-$
+$ 
 $ ******************************************************************************
 
 
@@ -228,9 +228,9 @@ $ MESSAGE 23 IN SET 3 WILL ONLY APPEAR IN THE DT ERRORLOG FILE
 
 $set 4
 $ *****  Module: DbReader.c  *****
-$
+$ 
 $  MESSAGES 1-11 IN SET 4 WILL ONLY APPEAR IN THE DT ERRORLOG FILE
-$
+$ 
 $ Do NOT remove the leading spaces from any of the lines of the following message.
 1 “%s”定义在文件：\n\
   “%s”\n\
@@ -288,9 +288,9 @@ $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
 
 $set 6
 $ *****  Module: ActionDb.c  *****
-$
+$ 
 $  MESSAGES 1-11 IN SET 6 WILL ONLY APPEAR IN THE DT ERRORLOG FILE
-$
+$ 
 $ Do NOT remove the leading spaces from any of the lines of the following message.
 1 动作定义“%s”在文件\n\
   “%s”\n\