[ref] New communication protocol; checksum and timeouts
[add] Logger
[fix] Long debug session
[fix] tests
[fix] PING reserved on mega2560
[fix] NEVER return in a mutex acquired context git st!
[add] LOGLVL_... constants
[ref] pthread_cond_wait timeout is a warning
[fix] Condition
[enh] Allow to specify log level from CPPFLAGS
[fix] Forgot to tell triggers spontaneous changes to HAL socket
[add] Travis IRC notifications
[enh] Travis as IRC notices