Make the protocol advertise a requestable channel

Without this, telepathy-glib/empathy doesn't believe the protocol is
bonafide (i.e., implementing TP_PROTOCOL_FEATURE_CORE). Adding a dummy
gets empathy to display the protocol without needing to be patched \o/.

share/telepathy/managers/padfoot.manager

@@ -1,4 +1,5 @@
 [ConnectionManager]
+Interfaces=
 Name=padfoot
 BusName=org.freedesktop.Telepathy.ConnectionManager.padfoot
 ObjectPath=/org/freedesktop/Telepathy/ConnectionManager/padfoot
@@ -6,6 +7,16 @@ ObjectPath=/org/freedesktop/Telepathy/ConnectionManager/padfoot
 [Protocol delta]
 param-account=s required
 param-password=s required secret
+
+AuthenticationTypes=org.freedesktop.Telepathy.Channel.Type.ServerTLSConnection;
+ConnectionInterfaces=org.freedesktop.Telepathy.Connection.Interface.Requests;org.freedesktop.Telepathy.Connection.Interface.Contacts;
 EnglishName=Delta Chat
-VCardField=email
 Icon=im-delta
+Interfaces=
+RequestableChannelClasses=text;
+VCardField=email
+
+[text]
+org.freedesktop.Telepathy.Channel.ChannelType s=org.freedesktop.Telepathy.Channel.Type.Text
+org.freedesktop.Telepathy.Channel.TargetHandleType u=1
+allowed=org.freedesktop.Telepathy.Channel.TargetHandle;org.freedesktop.Telepathy.Channel.TargetID;