fw: fix error logging

- Keep track of logged exceptions inside log_error itself.
- signal: log the exception, if there is one  in the finally clause of
  the  signal wrapper; this will ensure that the error will be logged
  closer to the command that originated.
- entrypoint: use log.log_error for top-level error logging, rather than
  the  entrypoint logger directly; this will ensure that errors are not
  repeated unnecessarily.
- Log CTRL-C message at zeroth indent level to make it easier to see in
  the  non-verbose output where it occurred.

wa/framework/entrypoint.py

@@ -107,10 +107,9 @@ def main():
         command = commands[args.command]
         sys.exit(command.execute(config, args))
 
-    except KeyboardInterrupt:
-        logging.info('Got CTRL-C. Aborting.')
+    except KeyboardInterrupt as e:
+        log.log_error(e, logger)
         sys.exit(3)
     except Exception as e:  # pylint: disable=broad-except
-        if not getattr(e, 'logged', None):
-            log.log_error(e, logger)
+        log.log_error(e, logger)
         sys.exit(2)