Only detects mouse clicks. Though, "9" mode seems broken, or unsupported
or something? Probably need to upgrade to "1000" mode or higher, but
that also reports scrolling events and such, which don't want to steal
from the context we're running in just yet.
Instead of confining you to just the bottom row. 0,0 is bottom left.
Doesn't behave exactly as expected for non-zero column coordinates yet,
but all in due time.
Likewise for belt. This necessitates renaming the %mor blit for newlines
to %nel, making this require a new runtime version. That's fine, more
breaking changes are to follow.
