lavf/libssh: fix file mode

Signed-off-by: Lukasz Marek <lukasz.m.luki@gmail.com>
lavf/libssh: improve authentication

- Add authentication using keys
- Provide better message on fail

Signed-off-by: Lukasz Marek <lukasz.m.luki@gmail.com>
lavd/xv: report if no adaptor present.
Merge remote-tracking branch 'lukaszmluki/master'

* lukaszmluki/master:
  lavf/libssh: improve authentication
  lavf/libssh: fix file mode

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge remote-tracking branch 'cigaes/master'

* cigaes/master:
  lavd/xv: report if no adaptor present.

Merged-by: Michael Niedermayer <michaelni@gmx.at>