This change consists of two parts:
a) New logging functions/macros that understand special keywords,
   like "@device", "@topic", "@Error"; these keywords will be
   converted to key value pairs. For device and error the
   corresponding objects will also be stored in a special log
   context (BoltLogCtx).
b) Two log writer functions to log to the journal and standard
   streams. These writer functions will also make use of the
   BoltLogCtx during formatting.

Both parts should be used together but can also work independently.