Removes two experiments that did not work.

Typing as a physical keyboard did not make remote-desktop-style apps
take the keys, and keeping the keyboard on screen did not help where it
was meant to. The reason is structural: an IME exists only while an app
has started input, and what we send reaches the app through the
input-method path whatever we stamp on the event.

Everything else about hardware keys stays exactly as it was - the arrow
and function keys, Escape and Tab, the Ctrl/Alt/Meta chords sent as real
key events, the registered hardware shortcuts, and the physical-keyboard
Hangul mapping.
