The original reason for intercepting the escape key in onKeyPreIme()
was to prevent the escape key as being treated as the Back key before
reaching onKeyDown().
This seems no long necessary, and may mess up handling the ...+1
combination for escape on the Google Pixel C keyboard (see #27).
When mouse reporting is enabled, do not send mouse events on up
after a long press, since that causes e.g. the cursor to move in
vim when lifting the finger after long pressing for the menu.
