Initial checkin of qthid's fcd code.
Rename all fcd functions so that both pro and proplus can be compiled into the same binary.
Make the filenames more readable. Also finish renaming fcd -> fcdProPlus in fcd_pro_plus.c.
Refactor fcd_pro_plus so that all functions take a hid_device argument.
Refactor fcd_pro.c to add a hid_device argument to all functions.
Add index argument to fcd*Open functions.
Add fcd*CountDevices functions.
Move FCD_STATUS_ENUM to fcd_common.h.
Add initial unified API.
Add FCDGetType and FCDGetFirmwareVersion functions.
Add FCDSetFreqHz function.
Add more comments to the .h file.
Move all source files into src/.
Improve README and update copyright notices.
Add carpsd-fcd commandline FCD controller.
Add make install target.