Fix httpWrite() bug which caused a variety of errors.

Fix httpWrite() bug which caused a variety of errors.

cups/http.c:
    - httpConnectEncrypt(): Update DEBUG_printf.
    - httpPrintf(): Check return value of httpFlushWrite().
    - httpUpdate(): Check return value of httpFlushWrite().
    - httpWrite(): Save bytes written in "bytes" instead of
      "length" and update DEBUG_printf's.
    - http_write_chunk(): Add DEBUG_printf's.

scheduler/client.c:
    - CloseClient(): Close pipes and files before socket.
    - WriteClient(): Add L_DEBUG2 log messages.

git-svn-id: svn+ssh://src.apple.com/svn/cups/cups.org/trunk@4707 7a7537e8-13f0-0310-91df-b6672ffda945