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/C/config/sys.resources.tmsg

@@ -25,7 +25,7 @@ $ *                         \t                  horizontal tab
 $ *                         \ (at end of line)  continue on same line
 $ *
 $ *****************************************************************************
-$
+$ 
 $ ----------------------------------------------------------------------------
 $ Do not translate message 1 and 3.
 $ This is not a message, but a locale dependent value.
@@ -38,29 +38,29 @@ $ *
 $ * 1 "/usr/dt/config/german/sys.font"
 $ *
 1 "/usr/dt/config/C/sys.font"
-$
+$ 
 $ Message 2 is not used...
-$
+$ 
 $ 2 
-$
+$ 
 $ Message 3:
 $ promptDialog.bboard.frame.form.text.columns = 45 for single-byte
 $                                               23 for multi-byte
-$
+$ 
 3 45
-$
+$ 
 $ Message 4 is not used...
-$
+$ 
 $ 4 
 $ 
 $ Messages 5-9 are labels for the file selection box.  They need to be 
 $ set globally for CDE. Don't translate the ':'.
-$
+$ 
 5 Enter path or folder name:
 6 Update
 7 Enter file name:
 8 Folders
-$
+$ 
 $ *XmFileSelectionBox*XmLabelGadget.fontList     
 $ This is not a message, but locale dependent values. See sys.font.tmsg...
 $