Fix Win32 get_key (#819)
Fix Win32 get_key (#819)

PR #711 moved the arrow and cancel key codes to `const.py`. However, the
move also changed the codes from byte arrays to strings, which broke the
use of `msvcrt.getch()` for Windows.

The fix is to use `msvcrt.getwch()` so the key is a Unicode character,
matching the Unix implementation.
scorphus/thefuck,SimenB/thefuck,nvbn/thefuck,SimenB/thefuck,nvbn/thefuck,scorphus/thefuck