SFTP quote command reported by Vincent Le Normand, but left it disabled.

reproduce the --ftp-create-dirs problem reported by Brian Ulm, but that
seems to need a call curl_easy_reset() which this test case doesn't do.

(test 620 tests the just-fixed problem reported by Brian Ulm).

files, as questioned by Mike Protts. SFTP does for me but SCP doesn't
so test 617 is disabled for now.

test code. Thanks to his curl_easy_setopt() typechecker work...

whole operation completes or an unrecoverable condition is detected

Changes introduced in revision 1.43 were useless

and the string contains a newline...

  such as the CURLOPT_SSL_CTX_FUNCTION one treat that as if it was a Location:
  following. The patch that introduced this feature was done for 7.11.0, but
  this code and functionality has been broken since about 7.15.4 (March 2006)
  with the introduction of non-blocking OpenSSL "connects".

  It was a hack to begin with and since it doesn't work and hasn't worked
  correctly for a long time and nobody has even noticed, I consider it a very
  suitable subject for plain removal. And so it was done.

Remove redundant and unreachable log message.

Log some more error descriptions.

when verifying the https and ftps servers

timeout passed to startnew, when this happens startnew completes without being
able to read the pidfile and consequently returns a zero pid2.

To fix the above posibility the server pid is recovered from the verification
stage which will actually return the server pid when verification is valid.

Make sure that the sftp client tool uses the ssh client binary that we have
used to generate the configuration files, otherwise sftp might be using one
located in the preferred path compiled into sftp.

Removed a few unnecessary requires SSL statements.