Function authority_after_crl 

pub fn authority_after_crl(
    edges: &[NQuin],
    root_authority: u64,
    crl: &[u64],
    agent: u64,
) -> bool

Does agent still hold authority from root_authority after excising EVERY node on the revocation list crl (a real-time CRL check across the whole chain)? Zero-heap (bounded BFS).