Reads the log of a lambda

Its requests, what its code printed, and what the server said while serving it - a handler that threw, a request that timed out. Oldest first. To follow it, pass the cursor of each answer as since of the next; missed says how many lines went by unread in between. Requests are logged as warnings when they were answered with a client error and as errors with a server error. The previews of its features have logs of their own.