Implement Combining Accents (dead keys) for physicial keyboards.

Also known as "Dead Keys".

Example:

In preferences set "Default to UTF-8".
Attach a hardware bluetooth keyboard.
Type Right-Alt-`
At this point you'll see a ` character in the cursor.
Type e
At this point you will see è appear. (If not, check that the
Default to UTF-8 preference is set correctly.)

Hat tip to the ConnectBot TermKeyListener.java source code.