- Remove legacy non-streams code (as discussed with Brad).

- Remove legacy non-streams code (as discussed with Brad).
- Make get_http_header_value() work using case-insensitive compares
  for the header names, as per relevant RFC's.
- General performance boost for get_http_headers().
- Fix a crash bug when a malformed URL is passed to the soap client.
- Implement https:// support in the the soap client. (does not verify
  the remote server certificate; it provides an encrypted link only).
- Provide a hook for libxml to parse files using any registered PHP
  wrapper, including https://, ftps:// and any user-space streams.