CVG: Insert a blank HISTORY line before the records.

This is to discriminate continuation lines recently introduced
into FITSIO and subsequent records.  COF_MHISR (4acde70)
will recognise this as the end of the multi-line text.

It is part of the solution to Issue #32.

libraries/cvg/cvg_whisr.f

@@ -32,6 +32,7 @@ SUBROUTINE CVG_WHISR( NDF, FUNIT, STATUS )
 
 *  Copyright:
 *     Copyright (C) 1997 Central Laboratory of the Research Councils.
+*     Copyright (C) 2013-2014 Science & Technology Facilities Council.
 *     All Rights Reserved.
 
 *  Licence:
@@ -60,7 +61,11 @@ SUBROUTINE CVG_WHISR( NDF, FUNIT, STATUS )
 *        Original version.
 *     19-NOV-2013 (DSB):
 *        Moved from CONVERT to CVG.
-*     {enter_changes_here}
+*     2014 May 6 (MJC):
+*        Put an empty HISTORY line after Dataset so that parsing by
+*        COF_MHISR can disriminate from recently introduced continuation
+*        line and the start of records.
+*     {enter_further_changes_here}
 
 *-
 
@@ -200,6 +205,11 @@ SUBROUTINE CVG_WHISR( NDF, FUNIT, STATUS )
      :                     STATUS )
             CALL FTPHIS( FUNIT, HISTRY, FSTAT )
 
+*  Write a blank header to separate the Dataset from the records.
+*  FTPHIS does nothing is given blank history text.
+            HISTRY = 'HISTORY    '
+            CALL FTPREC( FUNIT, HISTRY, FSTAT )
+
 *  Write the associated history text to the headers.
             CALL NDF_HOUT( NDF, IREC, CVG_HECHO, STATUS )