BUG/MEDIUM: h2: restart demuxing after releasing buffer space

Since the connection changes in 1.9, some breakage happened to the H2 mux
whose initial design was heavily relying on the fact that connection-level
functions were woken up after data were transferred to the stream layer.

We need to wake the demux up after receiving such data if the demux is
blocked. This at least allows to receive POSTs again. One issue remains,
it looks like the end of the uploaded data is silently discarded if the
server responds before the end of the transfer (H2 in half-closed(local)
state), which doesn't happen with 1.8.14 and nghttp as the client.

No backport is needed.
1 file changed