FERGUSON, Mo. (Reuters) - Honking horns and banging a metal bucket, a small but growing group of protesters awaited Monday's grand jury decision, swarming the Ferguson Police Department and meeting briefly with the father of slain black teen Michael Brown. Mike Brown Sr., whose unarmed son was killed by a white police officer on Aug. 9, slowed down in a car to chat with demonstrators after hearing that the secret panel had reached a decision on whether to indict Officer Darren Wilson in the Aug. 9 shooting. Protester Byron Conley, father of a teen son, said he spoke with Brown...