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.
