Our json implementation did not conform to the spec, and
was missing support for escpaed characters and exponental
numbers. This fixes it, and adds support for reading/writing
json directly from/to a stream.
There are two things left unimplemented. We could use a
"to_json" iface/impl, but that really needs traits to cut
down on code duplication. The other is it wouldn't be that
not that hard to turn this implementation into a event driven
parser like YAJL, but I ran into some type-inference bugs,
so I cut that out. It'd be nice to revisit this in the future
though.
Now that core exports "option" as a synonym for option::t, search-and-
replace option::t with option.
The only place that still refers to option::t are the modules in libcore
that use option, because fixing this requires a new snapshot
(forthcoming).