Updates /app/herm and dependencies to work with latest dill, and
rewrites the entire webterm frontend to use xterm.js for rendering.
Webterm code needs a bit more work. Its subscription handling might
want to be moved out, it needs to handle resizing, react to landscape
theme changes, etc.
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.
Make the marks produce json arrays where the (list @c) type is used.
On the frontend, transform the semantic (character-based) cursor
position into a byte-based one, in order to ensure the cursor gets
rendered at the correct location, even if the presence of multi-byte
characters like emoji.
Listens to the default dill session and passes its %blits on to
subscribers. Passes any %belt pokes it gets into dill.
Updates webdojo to make use of it, which is the primary motivation for
herm's existence.
