Fixes a translucency bug from 0.1.96: the frame added for the system's
bottom buttons painted the whole window, so the floating keyboard, the
Hanja and code-point panels and the notepad all stopped being
see-through. Only the reserved strip is painted now.

The notepad's bottom row was pushed off the screen by the same frame,
where it was invisible but still pressable. It measures itself against
what is left now.

The bottom strip is smarter: nothing is reserved on a phone that draws
no keyboard buttons down there, and settings can force it always or
never - and shows what your phone actually reports.

The 123 keypad on the 12-key layouts is the Keypad layout's own cells
now, holds and all, instead of a second set that held nothing.

New, off by default: Type as a physical keyboard. It sends keys the way
a physical keyboard does, for remote-desktop clients and other apps that
ignore soft-keyboard input. Korean has no key to be pressed on and is
still sent as text.
