Library changes:
- The library now re-enables learning and forwarding on all ports when STP is stopped.
- Slightly reduced memory usage by removing some unused structure members.
Added sample embedded applications for the following platforms:
- MK66F + KSZ8794
- STM32 + 88E6352
- TM4C129 + 88E6352
Changes in the Windows Simulator source code, mostly refactoring.