Need enum to choose big/little

[damody]

like this

enum ByteOrder {
BigEndian,
LittleEndian,
}

then we can use the struct like parameter
like this

pub fn hello(order:ByteOrder) ->() {
    let mut rdr = Cursor::new(vec![2, 5, 3, 0]);
    match order {
    BigEndian => rdr.read_u16::<BigEndian>().unwrap();
    LittleEndian => rdr.read_u16::<LittleEndian>().unwrap();
    _=>()
    }
}

[BurntSushi]

This issue is drastically under specified, and I believe it is a duplicate of #95.