Documentation fix and v1.1.2 release.

Port ncurses 6.1 compatibility fix from termbox-go.

Issue: nsf/termbox-go#185

Fixes #111.

Update README with more 1.1.0 changes, and let's tag a release.

Docstrings for Termbox.height() and Termbox.width() were inverted, fi…

…xed.