when doing marked spell-check, properly handle the case where the mark

ends in the middle of a word and that word is spell-checked; also move
the logic to detect an upside-down mark to mark_order() instead of using
the same logic in three different places, and rename a few variables for
consistency


git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@2070 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

src/files.c

@@ -1760,7 +1760,7 @@ int write_marked(const char *name, int tmp, int append)
     /* Partition the filestruct so that it contains only the marked
      * text. */
     mark_order((const filestruct **)&top, &top_x,
-	(const filestruct **)&bot, &bot_x);
+	(const filestruct **)&bot, &bot_x, NULL);
     filepart = partition_filestruct(top, top_x, bot, bot_x);
 
     /* If the line at filebot is blank, treat it as the magicline and