added initial V-USB support for HHKB

move files: main_vusb.c ps2_usart.c sendchar_usart.c from ps2_usb to common dir

fix bug: send Fn key even after the layer is used.

ad hoc fix for IDLE bug which affects on Mac only.

fix for ps2_usb Makefile and circuit

minor fix for HHKB Makefile and doc

FIX: send last report when idle timeouts. (pjrc)

ADD: V-USB Circuit in README

FIX: host_get_first_key in vusb/host.c

v3.0    cleanse files

fixed hhkb to comply new API.

fixed macway to comply new API.

fixed adb_usb to comply new API.

integrate V-USB support into ps2_usb

Synchronous USART support for PS/2 on V-USB stack

PS/2: request to resend when error is occured.

fixed: not to send key if fn_keycode is modifier

host interface for pjrc

refactor keyboard.h, host.h

added protocol stack: pjrc, vusb