Support gzip/deflate on HTTP connections.

Support gzip/deflate on HTTP connections.

Add httpConnect2, httpAddrCopyList, and several other new (stub, for now) APIs
to better support network connections and server implementations on top of
public API.

Update _httpCreate to support client/server mode and blocking behavior.

Deprecate httpConnect, httpConnectEncrypt, and httpReconnect.

Promote _httpAddrPort and _httpPeek to public API.

Add HTTP_FIELD_ACCEPT_ENCODING, HTTP_FIELD_ALLOW, and HTTP_FIELD_SERVER fields.

Add HTTP_STATE_ERROR and HTTP_STATE_UNKNOWN http_t states.

git-svn-id: svn+ssh://src.apple.com/svn/cups/cups.org/trunk@10672 7a7537e8-13f0-0310-91df-b6672ffda945