Added a common database backend implementation.

Added sqlite (proof of concept)

persistence/implementation/common/model/cms_user.e

@@ -0,0 +1,68 @@
+note
+	description: "Summary description for {USER}."
+	date: "$Date$"
+	revision: "$Revision$"
+
+class
+	CMS_USER
+
+create
+	make
+
+feature {NONE} -- Initialization
+
+	make (a_name: READABLE_STRING_32)
+			-- Create an object with name `a_name'.
+		do
+			name := a_name
+		end
+
+feature -- Access
+
+	id: INTEGER_64
+		-- Unique id.
+
+	name: READABLE_STRING_32
+		-- User name.
+
+	password: detachable READABLE_STRING_32
+		-- User password.
+
+	email: detachable READABLE_STRING_32
+		-- User email.
+
+feature -- Change element
+
+	set_id (a_id: like id)
+			-- Set `id' with `a_id'.
+		do
+			id := a_id
+		ensure
+			id_set: id = a_id
+		end
+
+	set_name (n: like name)
+			-- Set `name' with `n'.
+		do
+			name := n
+		ensure
+			name_set: name = n
+		end
+
+	set_password (p: like password)
+			-- Set `password' with `p'.
+		do
+			password := p
+		ensure
+			password_set: password = p
+		end
+
+	set_email (m: like email)
+			-- Set `email' with `m'.
+		do
+			email := m
+		ensure
+			email_set: email = m
+		end
+
+end