[cppmyth] CleanHanging for all proto connections
[cppmyth] If any hang returns < 0
[cppmyth] Auto retry when open connection failed

Until explicit close, retry to open.
Explicit close will reset hang to disable retry.
[cppmyth] Anyway keep track of blockShutdown

On command failed, we retry at next open.
[cppmyth] Bump version 1.0.6