Fixed various CMS_MODULE.install, by not marked module installed if an error occurred!

Improved Auth related module implementation by having a way to change settings like token, max age.
  - use CMS_SETUP.site_id and related "auth.$module.token" ... configuration values.
  - removed related CMS_..._CONSTANTS classes.

For auth session module, use auth_session as table name, and use VARCHAR(64).
Extracted sql from blog module, and store it under site/scripts/install.sql .
Renamed a few $modulename.sql as install.sql

modules/session_auth/cms_session_api.e

@@ -6,7 +6,6 @@ note
 class
 	CMS_SESSION_API
 
-
 inherit
 	CMS_MODULE_API
 
@@ -19,9 +18,25 @@ feature {NONE} -- Initialization
 
 	make_with_storage (a_api: CMS_API; a_session_auth_storage: CMS_SESSION_AUTH_STORAGE_I)
 			-- Create an object with api `a_api' and storage `a_session_auth_storage'.
+		local
+			s: detachable READABLE_STRING_8
 		do
 			session_auth_storage := a_session_auth_storage
 			make (a_api)
+
+				-- Initialize session related settings.
+			s := a_api.setup.string_8_item ("auth.session.token")
+			if s = Void then
+				s := a_api.setup.site_id + default_session_token_suffix
+			end
+			create session_token.make_from_string (s)
+
+			s := a_api.setup.string_8_item ("auth.session.max_age")
+			if s /= Void and then s.is_integer then
+				session_max_age := s.to_integer
+			else
+				session_max_age := 86400 --| one day: 24(h) *60(min) *60(sec)
+			end
 		ensure
 			session_auth_storage_set:  session_auth_storage = a_session_auth_storage
 		end
@@ -31,6 +46,17 @@ feature {CMS_MODULE} -- Access: User session storage.
 	session_auth_storage: CMS_SESSION_AUTH_STORAGE_I
 			-- storage interface.
 
+feature -- Settings
+
+	default_session_token_suffix: STRING = "_SESSION_TOKEN_"
+			-- Default value for `session_token'.
+
+	session_token: IMMUTABLE_STRING_8
+			-- Token used for the session related cookies.
+
+	session_max_age: INTEGER
+			-- Value of the Max-Age, before the cookie expires.
+
 feature -- Access
 
 	user_by_session_token (a_token: READABLE_STRING_32): detachable CMS_USER