Use Log#emit and Log::Metadata #3986

Job	Run time
Format check	19s
Lint check	1m 5s
Lint OpenAPI	16s
Lint javascript	15s
Spec	27m 38s
Spec OS X	3m 12s
Compile LavinMQ	1m 9s
Spec FreeBSD	5m 54s
Filters for fronted specs	3s
Bunny client test	2m 29s
RabbitMQ HTTP API Go client test	1m 8s
Test in release mode	19s
RabbitMQ java client test	4m 26s
RabbitMQ HTTP API Ruby client test	49s
Fronted specs	0s
	49m 2s

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