Added HTTP_DATE to ease http date manipulation and optimize code rather than using EiffelTime's code facilities.

Added autotests to `http' lib.

library/network/protocol/http/src/http_header.e

@@ -160,7 +160,7 @@ feature -- Conversion
 				loop
 					append_line_to (c.item, a_result)
 				end
-			end			
+			end
 		end
 
 feature -- Access
@@ -763,8 +763,11 @@ feature {NONE} -- Implementation
 
 	date_to_rfc1123_http_date_format (dt: DATE_TIME): STRING_8
 			-- String representation of `dt' using the RFC 1123
+		local
+			d: HTTP_DATE
 		do
-			Result := dt.formatted_out ("ddd, [0]dd mmm yyyy [0]hh:[0]mi:[0]ss") + " GMT"
+			create d.make_from_date_time (dt)
+			Result := d.string
 		end
 
 feature {NONE} -- Constants