The serial code was Linux/Mac only and utilised termio/tcsetattr
functions that were not available on Windows platforms. This patch
ports the serial code to the Windows APIs using the same approach
as the Computrainer.cpp code. It allows us to support old-style
serial download cables on Windows. (We already supported them on
Mac and Linux.)
I hate to change so many lines of code just for a little rename, but I want to
distinguish between "devices", like the PowerTap and SRM, and "communications
ports", like the serial port and the native D2XX drivers. This work is in
preparation for adding direct download support for the SRM.
