[mythtv] Start handler once all are initialized
[cppmyth] Auto retry when open connection failed

Until explicit close, retry to open.
Explicit close will reset hang to disable retry.
[cppmyth] When disconnected then close all

Close schedule manager too. Then re-open when connected.
[mythtv] Handle power saving

When GUI becomes deactivated then allow backend shutdown
and disable wake on lan. Revert when GUI becomes activated.
[mythtv] Enable/Disable power saving mode
[mythtv] Close all on sleep

Close schedule manager too.
Re-order sequence for close and open.
[mythtv] Handle host_ether changes
[cppmyth] Anyway keep track of blockShutdown

On command failed, we retry at next open.