Update documentation for TC and TCN callbacks
Write documentation for onConfigChanged
Add UI for clearing the STP log
Allow creation of bridges with user-specified number of ports and MSTIs
Add "timestamp" parameter to CallTcCallback
Simulator: Show some message when BPDUs can't be sent due to TxHoldCount
Implement code that calls STP_CALLBACKS::onTopologyChanged
File -> Open should not open an already open file