Changes made for Pathfinder V5 PC's.

The core problem was that the code assumed master and slave would always be the same board revision (e.g., both Rev G), but in practice they can differ — like a Rev E/F master with a Rev G slave, or vice versa.

Firmware file selection: The slave programming was using Board1Type (master's board type) to select the firmware file instead of Board2Type. So if the master was Rev F and the slave was Rev G, the slave would get flashed with the Rev F firmware. Fixed by using Board2Type for the slave's firmware stream lookup.

Post-flash version check: After programming, the code compared the master's version against the slave's version and errored if they didn't match. But they're supposed to be different — Rev E/F and Rev G use different firmware files with different version numbers. Fixed by checking each controller individually against its own required firmware version (looked up from its own board type's firmware file).

Revision display: The dialogs only showed the master's revision info. Updated AvailableFlashDialog to show labeled master and slave sections (revision, current version, required version), and updated IsValidToFlash to display both "Master is Rev X" and "Slave is Rev Y" in the programming status dialog. Also added a slave validation check after RetrieveBoardData to catch board data mismatches before flashing the slave.