wip/libspt 1.1 NetBSD

On many platforms terminal emulators need some privilege for some functionalities. Especially, they need root privilege on BSDs to prevent other users from peeking user's input. With libspt you can drop all privileges of your terminal emulator. Additionally libspt saves terminal emulator writers many portability related headaches. (Yes, there is many headaches.)

From libspt-0.2 it also provides a minimal termios(termio/sgtty) wrapper functionality. It does not support any customization nor complex settings but enables you to implement easiest functionalities portably with least work.