Improve wording of a couple of debug messages.

found or the OpenSSH version found

keys that small.

really reduce security since in the common case of a daily automated build
the keys are only used for a single test run lasting a few minutes before
being deleted.

sftp tests run fine on gentoo

Added more options to the ssh config file to improve the consistency of
the test environment.
Force a rewrite of the ssh config files on every invocation.
Changed the opens to work on older versions of perl.

openssh

Try to avoid this problem checking for some possible unsupported options,
and avoid using them in the configuration file.

in the PATH and afterwards in other common locations.

before resorting to the kill -9 hammer.

Added test harness infrastructure to support scp/sftp tests, using
OpenSSH as the server.