Fix uv_tty_set_mode raw mode not being raw enough

Remove output CR translation (and output postprocessing), parity generation/checking from uv_tty_setmode.

I was attempting to use Terminals.raw! to implement clean I/O with a pty, but noticed that the output wasn't as expected, with LF being translated to CRLF by the line driver. `uv_tty_set_mode` seems pretty old in libuv, I doubt anybody ever noticed. The settings now match the Python tty.setraw module.

I use it here: https://github.com/wavexx/Expect.jl/blob/master/src/Expect.jl