- Don't apply endian conversions to flags, which are 8 bits.
- Use #defines for default times for use outside library.
- Clarify our behavior when in STP_DISABLED state.
- Add "aux" member to STP port struct to be able to refer back to
the owning port.
- Define macros to print STP bridge and port ids.
- New helper function to get port id.
- New helper function to convert speed to cost.
- New functions to describe current role of port.