Fix blocking while waiting for key

The timeout() for input is set on main window (stdscr), since it seems
that for some ncurses implementations get_wch and getch are the same
(non widechar) wget_wch is used instead. The window passed must the
the main one, the others doesn't have the timeout settings. Another
option is to set wtimeout() on every window.
Merge pull request #17 from manuel-arguelles/fix_blocking

Fix blocking while waiting for key