Removed shared_error from CMS_API

Added Missing theme and Missing tempalte classes.
Updated CMS_RESPONSE to handle missing template and send a 503 status code
with a raw response.

library/src/theme/missing_theme/missing_cms_template.e

@@ -0,0 +1,42 @@
+note
+	description: "Summary description for {MISSING_CMS_TEMPLATE}."
+	author: ""
+	date: "$Date$"
+	revision: "$Revision$"
+
+class
+	MISSING_CMS_TEMPLATE
+
+inherit
+
+	CMS_TEMPLATE
+
+create
+	make
+
+feature {NONE} -- Implementation
+
+	make ( a_theme: MISSING_CMS_THEME)
+		do
+			theme := a_theme
+		end
+
+feature -- Access
+
+	theme: MISSING_CMS_THEME
+
+	variables: STRING_TABLE [detachable ANY]
+		do
+			create Result.make (0)
+		end
+
+	prepare (page: CMS_HTML_PAGE)
+		do
+		end
+
+	to_html (page: CMS_HTML_PAGE): STRING
+		do
+			Result := " "
+		end
+
+end

library/src/theme/missing_theme/missing_cms_theme.e

@@ -0,0 +1,45 @@
+note
+	description: "Describe a missing theme."
+	date: "$Date$"
+	revision: "$Revision$"
+
+class
+	MISSING_CMS_THEME
+
+inherit
+
+	CMS_THEME
+
+create
+	make
+
+feature {NONE} -- Initialization
+
+	make (a_setup: like setup)
+		do
+			setup := a_setup
+		ensure
+			setup_set: setup = a_setup
+		end
+
+feature -- Access
+
+	name: STRING = "missing theme"
+
+	regions: ARRAY [STRING]
+		do
+			create Result.make_empty
+		end
+
+	page_template: CMS_TEMPLATE
+			-- theme template page.
+		do
+			create {MISSING_CMS_TEMPLATE} Result.make (Current)
+		end
+
+	page_html (page: CMS_HTML_PAGE): STRING_8
+		do
+			to_implement ("Add a better response message, maybe using smarty template")
+			Result := "Service Unavailable"
+		end
+end