Some http robustness improvements.
- Increase the maximum response header buffer size up to ~32 kB. This also moves it into a heap-allocated buffer instead of the stack, as 32 kB is really too much for the stack. - Treat LF as CR LF when parsing headers. This is necessary when parsing the load-balancer response in front of <http://lazaradio.hu:8100/bermuda.opus>. The response returned by that server is invalid in lots of ways, but with these two changes we can read it. - In addition, we now peek ahead at a large chunk of data when reading the response instead of reading 2 to 4 bytes at a time. This allows a typical response to be read with two syscalls (one peek, one read) instead of several hundred. - Stop trying to read more data when the connection is closed.