Fix: Unify termios types for actions & flags

[tomaskallup]

The type for Tcflags was used instead of the CInt (now Tcactions) and vice versa.

This required some explicit casts when working with termios:

termios.c_lflag &= (Tcflags)~(termios::ICANON | termios::ECHO);
termios.setAttr(self.fd, (int)termios::TCSANOW);

With this PR, it can just be:

termios.c_lflag &= ~(termios::ICANON | termios::ECHO);
termios.setAttr(self.fd, termios::TCSANOW);

It should also reflect what the C implementation has.

[lerno]

Looks correct. Can you add a test too?

[lerno]

Nevermind, it would only be run on some platforms.

[lerno]

Thank you!