Using absl.app causes flags to be handled automatically and gives us nice things like app.UsageError. I've added extra checks for unspecified flags, since otherwise the error messages caused by these flags being unset were quite obtuse. I've removed the default value for --log_list_schema since there is no schema file found at "data/log_list_schema.json".
Latest commit 1e90c61
Sep 10, 2018