Change tundra.tn:log to add $context input variable which allows
arbitrary information to be appended to $message prior to logging
Change tundra.tn:deliver to include delivery duration in success
activity log statement; closes #34
Change tundra.tn:process to include processing duration in success
activity log statement; closes #35
Change tundra.tn:amend to include processing duration in success
activity log statement
Change tundra.tn:branch to include processing duration in success
activity log statement
Change tundra.tn:process to include splitting and routing durations
in relevant activity log statements; closes #37
Change tundra.tn:translate to include processing duration in success
activity log statement; closes #36
Change tundra.tn:chain to include processing duration in success
activity log statement
Change tundra.tn:derive to include processing duration in success
activity log statement
Change tundra.tn:enqueue to include processing duration in success
activity log statement
Change tundra.tn:deliver to log processing attempt and success when
a $service is specified