Add mod_mam header file

include/mod_mam.hrl

@@ -0,0 +1,15 @@
+-record(archive_msg,
+	{us = {<<"">>, <<"">>}                :: {binary(), binary()} | '$2',
+	 id = <<>>                            :: binary() | '_',
+	 timestamp = p1_time_compat:timestamp() :: erlang:timestamp() | '_' | '$1',
+	 peer = {<<"">>, <<"">>, <<"">>}      :: ljid() | '_' | '$3' | undefined,
+	 bare_peer = {<<"">>, <<"">>, <<"">>} :: ljid() | '_' | '$3',
+	 packet = #xmlel{}                    :: xmlel() | '_',
+	 nick = <<"">>                        :: binary(),
+	 type = chat                          :: chat | groupchat}).
+
+-record(archive_prefs,
+	{us = {<<"">>, <<"">>} :: {binary(), binary()},
+	 default = never       :: never | always | roster,
+	 always = []           :: [ljid()],
+	 never = []            :: [ljid()]}).