GeezerVison

Manual backport of #156354.

window.encoding does not encode the string arguments on a build with wide-character support: the curses library converts the characters itself.

In the HOWTO: getch() returns -1, not curses.ERR, when there is no input, and half-delay mode does the same as no-delay mode. getkey() returns the key name only for a special key. leaveok() is not a synonym for curs_set(). getstr() returns a bytes object, interprets the erase and kill characters, and limits bytes. The ACS_* constants are not all larger than 255. Also document get_wch() before getch(), and read whole characters in the example.

The mentions of complexchar, complexstr, in_wch(), in_wchstr() and get_wstr() are omitted: these do not exist in 3.15.

(cherry picked from commit 161054c)

• Issue: curses window.encoding does not encode str arguments on a wide build #156347