release the next curl until there is a libssh2 0.16 released.

passed to it with curl_easy_setopt()! Previously it has always just refered
to the data, forcing the user to keep the data around until libcurl is done
with it. That is now history and libcurl will instead clone the given
strings and keep private copies.

issue is in libssh2 and not freeing a dynamic error message during cleanup.

* Move scp:// into a state machine so it won't block in multi mode
* When available use the full directory entry from the sftp:// server

message for an scp:// upload failure.  If libssh2 has his matching
patch, then the error message return by the server will be used instead
of a more generic error.

and CURLOPT_NEW_DIRECTORY_PERMS.  These control the premissions for files
and directories created on the remote server.  CURLOPT_NEW_FILE_PERMS
defaults to 0644 and CURLOPT_NEW_DIRECTORY_PERMS defaults to 0755

other authentication methods.  Terminate with a memory error.

allocated when needed

Caught by the auto-builds

only affected sftp_sendquote() for the "chgrp/chmod/chown" commands.

This also fixed failure of test 614 on a system that previously failed.

with the latest libssh2, the listing would be truncated at the symlink.
Fix by looping on LIBSSH2_ERROR_EAGAIN, like the rest of the calls.

uses the --ftp-create-dirs flag to control if cURL will try and create
directories that are specified in an upload path, but don't exist.

ie 0.14, that don't know about newer constants used in the state machine.

  libssh2_sftp_shutdown() and libssh2_session_free() can now return
  LIBSSH2_ERROR_EAGAIN.

* Fix the _send() and _recv() return values so non-blocking works

suite, transfer fails in the real world.  So after connect set to blocking
as full non-blocking is migrated out.

LIBSSH2_APINO >= 200706012030.  More to come...

memory leak, and it is the right thing to do.

* As of (LIBSSH2_APINO >= 200706012030) there are not *nb() functions
* As of (LIBSSH2_APINO >= 200706012030) most libssh2_*() functions
  can return LIBSSH2_ERROR_EAGAIN to indicate that the call would block.

To make the code work as previously, blocking, all the code has been
updated so that when (LIBSSH2_APINO >= 200706012030) it loops simulating
blocking.  This allows the existing code to function and not hold up
the upcoming release.

case 614.
Allow SFTP quote commands chmod, chown, chgrp to set a value of 0.

sftp didn't truncate it first, which would corrupt the file if the new
file was shorter than the old.

because I just made SCP uploads return this value if the file size of
the upload file isn't given with CURLOPT_INFILESIZE*. Docs updated to
reflect this news, and a define for the old name was added to the public
header file.