UART object now uses a stream-like interface: read, readall, readline,
readinto, readchar, write, writechar.
Timeouts are configured when the UART object is initialised, using
timeout and timeout_char keyword args.
The object includes optional read buffering, using interrupts. You can set
the buffer size dynamically using read_buf_len keyword arg. A size of 0
disables buffering.
Recent changes to builtin print meant that print was printing to the
mp_sys_stdout_obj, which was sending data raw to the USB CDC device.
The data should be cooked so that \n turns into \r\n.
Blanket wide to all .c and .h files. Some files originating from ST are
difficult to deal with (license wise) so it was left out of those.
Also merged modpyb.h, modos.h, modstm.h and modtime.h in stmhal/.
It's really a UART because there is no external clock line (and hence no
synchronous ability, at least in the implementation of this module).
USART should be reserved for a module that has "S"ynchronous capabilities.
Also, UART is shorter and easier to type :)