Added CMS_STRING_EXPANDER.

For now with basic implementation.
  It will be improved later

Added SEO related attribute in CMS_RESPONSE.
Added improved Contact module.
Added basic SEO module.

modules/contact/src/contact_api.e

@@ -0,0 +1,40 @@
+note
+	description: "API for the contact module."
+	date: "$Date: 2015-05-22 23:00:09 +0200 (ven., 22 mai 2015) $"
+	revision: "$Revision: 97349 $"
+
+class
+	CONTACT_API
+
+inherit
+	CMS_MODULE_API
+		rename
+			make as make_api
+		end
+
+	REFACTORING_HELPER
+
+create
+	make
+
+feature {NONE} -- Initialization
+
+	make (a_api: CMS_API; a_contact_storage: like contact_storage)
+			-- <Precursor>.
+		do
+			make_api (a_api)
+			contact_storage := a_contact_storage
+		end
+
+feature {CMS_MODULE} -- Access nodes storage.
+
+	contact_storage: CONTACT_STORAGE_I
+
+feature -- Basic operation
+
+	save_contact_message (msg: CONTACT_MESSAGE)
+		do
+			contact_storage.save_contact_message (msg)
+		end
+
+end