This fixes #10260 by pulling in
servo/ipc-channel#61 (fix receive for messages
close to packet size) and servo/ipc-channel#62
(properly handle ENOBUFS); where the latter is not critical per se, as
there was a workaround already -- but that workaround aggrevated the
first bug, resulting in the urgent issue...

This bump requires a tidy override for `uuid`: `ipc-channel` was updated
to `uuid 0.2` in servo/ipc-channel#63 (don't
know why...), while other crates are still with `0.1`. That was blocking
this urgent bug fix; and according to a discussion with @mbrubeck on
IRC, the override should be OK in this case.