[cmyth] Add support for protocol version 76

This adds syndicatedepisode. partnumber and parttotal to program info.
MythTV changeset: d4dcff374e493c23392803134eaba12b02f780b0
[cmyth] Add support for protocol version 77

Add stub for cmyth_recorder_get_duration_map (FILL_DURATION_MAP).
MythTV changeset: 49dbed5be0729b04a5f0fd0426a32fceb2dd7935