rn42: Add commands for RN-42

rn42: Add rn42_getc and rn42_gets

Fxi layer stuck of keymap_hasu

- In mouse key layer with holding semicolon, press Fn0, release
  semicolon and release Fn0 now layer 1 is stuck.

Update doc

Change RN42 state display

Fix power saving while USB suspended

- doesn't pwoer save while Bluetooth turns on

Add wait for charging capacitance of ADC S/H

Fix: enable digital input for PF5

Clean ADC code of battery_voltage()

Disable input buffer for ADC

Update MEMO

Add LUFA device state to command info

Fix lufa sendchar() infinite wait loop

- FrameNumber is not updated when adapter powered
- can be blocked in sendchar() when pluged into AC adapter

Fix USB plug-in while BT mode falls to be enumerated

Compensate timer during prower down

hhkb: Add Makefile.jp for HHKB JP

Merge branch 'mbed_infinity'

infinity: Add initial files for keyboard support

infinity: Move project specific files to local

Fix linker script for NVIC vector on RAM