Expand CAN write logging to show the bus as well as ID and data.
Make sure CAN message list is consistently ordered.

Fixes problem with CAN writes where we were sending on the wrong bus.
Don't enqueue as many messages in emulator loop to avoid overflow.
Merge branch 'master' into next
Update changelog.
Doc that write messages are null separated, not newline.
Doc that write messages are null separated, not newline.
Set initial UART transmit interrupt status to get things going.

Fixed #77.

Conflicts:
	src/buffers.c
	src/lpc17xx/serialutil.c
Merge branch 'next' into v4.0

Conflicts:
	src/platform/lpc17xx/uart.cpp