Improved error library by refactorying the sync as two way propagation.

Now one can setup error handler propagation in one way, or two way (sync).
The "reset" applies in both way, even if this is a one way propagation to fit current existing usage.
Added optional id for the error handlers.
Feature renaming according to design changes.
Added related autotest cases.

library/utility/general/error/src/error_custom.e

@@ -16,13 +16,13 @@ create
 
 feature {NONE} -- Initialization
 
-	make (a_code: INTEGER; a_name: like name; a_message: detachable like message)
+	make (a_code: INTEGER; a_name: like name; a_message: detachable READABLE_STRING_GENERAL)
 			-- Initialize `Current'.
 		do
 			code := a_code
 			name := a_name
 			if a_message /= Void then
-				message := a_message
+				message := a_message.as_string_32
 			else
 				message := {STRING_32} "Error: " + a_name + " (code=" + a_code.out + ")"
 			end
@@ -45,7 +45,7 @@ feature -- Visitor
 		end
 
 note
-	copyright: "2011-2012, Eiffel Software and others"
+	copyright: "2011-2016, Jocelyn Fiat, Eiffel Software and others"
 	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
 	source: "[
 			Eiffel Software