Do the mappedKey lookup earlier, in handle_key_event, so that if any of
our handlers need to look at the mapped key, they do not have to look it
up themselves. This simplifies plugged hooks considerably, as they can
always assume that the mapped key they receive is correct. They still
receive enough information to do the lookup themselves, though, if they
ever need that.
Additionally, in handle_key_event_default, baseKey is only looked up if
mappedKey was NoKey. This is so that hooks can defer to this function,
via handle_key_event, setting their own mappedKey, without having to
worry about setting a row/col that would map to a special key on the
base layer.
Fixes#39.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>