Fixed assertion that were broken with recent delayed header response.

Changed semantic of put_header_lines and add_header_lines,
Now the arguments are iterable of string (i.e the header line)

The previous features were not used, and were not well named.
So we removed them, and reused the names for adpated implementation.

library/server/wsf/src/wsf_response.e

@@ -252,23 +252,23 @@ feature -- Header output operation: helpers
 			message_writable: message_writable
 		end
 
-	put_header_lines (a_lines: ITERABLE [TUPLE [name: READABLE_STRING_8; value: READABLE_STRING_8]])
+	put_header_lines (a_lines: ITERABLE [READABLE_STRING_8])
 			-- Put headers from `a_lines'
 		require
 			header_not_committed: not header_committed
 		do
 			across a_lines as c loop
-				put_header_line (c.item.name + ": " + c.item.value)
+				put_header_line (c.item)
 			end
 		end
 
-	add_header_lines (a_lines: ITERABLE [TUPLE [name: READABLE_STRING_8; value: READABLE_STRING_8]])
+	add_header_lines (a_lines: ITERABLE [READABLE_STRING_8])
 			-- Add headers from `a_lines'
 		require
 			header_not_committed: not header_committed
 		do
 			across a_lines as c loop
-				add_header_line (c.item.name + ": " + c.item.value)
+				add_header_line (c.item)
 			end
 		end
 
@@ -409,8 +409,7 @@ feature -- Response object
 		do
 			a_message.send_to (Current)
 		ensure
-			status_committed: status_committed
-			header_committed: header_committed
+			status_committed: status_is_set
 		end
 
 feature -- Redirect