Make the relay acknowledge all received commandsorigin/master

To that effect, bump liberty and the xC relay protocol version.
Relay events have been reordered to improve forward compatibility.

Also prevent use-after-free when serialization fails.

xP now slightly throttles activity notifications,
and indicates when there are unacknowledged commands.

1 files changed, 0 insertions, 0 deletions

diff --git a/liberty b/liberty
-Subproject af889b733e81fa40d7a7ff652386585115e186f
+Subproject 31ae40085206dc365a15fd6e9d13978e392f8b3