add build option USB_12KRO.

support 12KRO

add system controls(power down/wake up) from generic desktop page(HID)

add audio controls from consumer page(HID)

change hhkb/keymap

Merge branch 'led'

output previous key state on TP1684 when scaning  matrix.

FIX: LED debug

repeating Fn key: press twice quickly to repeat.

revise Fn key processing.

improve layer switching

ADD: macway/doc
FIX: keymap

v2.0: HHKB/Macway support merged

new build method for macway

ADD: keymap macro for human to read easier
ADD: controller.h for controller board definition(teensy)
ADD: debug toggle

FIX: include files

FIX: doc and keymap.

switch debug on/off by pressing 4 keys on booting time

add keymap layer: Matias half keyboard style(SPACE) [NOT USED]

hhkb: refactored