Initial Import: Database transaction handling.

Initial Import: Error handling using ewf error library.
Added a CMS_ERROR_FILTER as part of registered filters of CMS_SERVICE

persistence/implementation/common/database/database_no_change_error.e

@@ -0,0 +1,27 @@
+note
+	description: "Summary description for {DATABASE_NO_CHANGE_ERROR}."
+	author: ""
+	date: "$Date$"
+	revision: "$Revision$"
+
+class
+	DATABASE_NO_CHANGE_ERROR
+
+inherit
+	DATABASE_ERROR
+		redefine
+			make_from_message
+		end
+
+create
+	make_from_message
+
+feature {NONE} -- Init
+
+	make_from_message (a_m: like message; a_code: like code)
+			-- Create from `a_m'
+		do
+			make (a_code, once "Database No Change Error", a_m)
+		end
+
+end