Function dcc_event 

pub fn dcc_event(address: u16, long: bool, extra_flags: u8) -> EventId

Build the search event for a DCC address. Addresses above 127 are always long; long forces a long address for low numbers.

Sets EXACT | ADDRESS_ONLY | DCC, plus DCC_LONG_ADDRESS when needed, plus extra_flags (typically ALLOCATE and/or a speed-step value).