auth_rewrite update from Robert Collins

auth_rewrite update from Robert Collins

* src/authenticate.c
  (authenticateValidateUser): Check for user scheme data.
  Increase the debug level for "validated".
  (authenticateFixHeader): Add a hint for internal responses versus
  proxied responses. Use it to prevent erroneous challenges when external
  sites request authentication.

* src/client_side.c
  (clientRedirectDone): Reference lock any auth use when creating a
  new request.
  (clientBuildReplyHeader): Hint to authenticateFixHeader that this is
  a proxied response.

* src/errorpage.c
  (errorAppendEntry): Hint to authenticateFixHeader that this is an
  internal response.

* src/helper.c
  (helperStatefulSubmit): Handle broken allocators that don't clear memory.
  Better descriptive comments.
  Remove an redundant cbdata check.

* src/protos.h
  (authenticateFixHeader): New prototype.

* src/auth/basic/helpers/multi-domain-NTLM/README.txt
  Updated email address.

* src/auth/basic/helpers/multi-domain-NTLM/smb_auth.pl
  Disable debug mode for default.
  Replace actual machine names with samples.

* src/auth/ntlm/auth_ntlm.c
  (authNTLMParse): Disable pipelining if NTLM is configured to avoid
  race condition with IE misbehaving.