Initial implementation of RFC 5424 support (syslog protocol). Allows
users to force-format the syslog output in a RFC 5424 compatible way,
making NuttX systems 'originators' that are able to interface with
syslog 'collectors' and 'relays' (useful for logging to syslog servers).
In addition to regular formatting options for syslog output, users can
also add structured data (currently only timeQuality is implemented,
assuming no sync and no timezone is no known). Facilities and severities
now also follow RFC 5424. Support for additional features (like
more sdata elements, msgid, etc.) will need to be built into the syslog
implementation if desired.
