Add support for Include in ssh config (#70)

[edlmo]

This patch adds support for the Include directive in ssh_config files (issue #70).
It adds the included (readable) files to the config variable to be later processed by the _known_hosts_real() function.

[scop]

Thanks for looking into this. Comments:

_included_config_files is a too generic function name; this is for a very specific purpose.

But further, because the function is used only from one place and is specific to that particular case, I think it should be inlined in the caller function instead of having it as a separate function in the environment.

Test cases for the test suite are needed for verifying the intended functionality.

[edlmo]

Agree with the function name, it could be _included_ssh_config_files.

But I'm not so sure about moving that functionality inlined on _known_hosts_real. The ssh config allows to use the Include directive inside the included files... so the recursive function seems to be a good approach to me.

If you are ok with that I could change the function name and look into the test cases.

PD: thanks to you for bash-completion ;)

[scop]

Ah, I somehow missed that the includes and the function is recursive. In that case, agreed with the current approach.

[edlmo]

I've added a test case for the ssh_config Include functionality (fixing some bugs along the way).
(passes on ./runUnit _known_hosts_real.exp)

[scop]

LGTM, thanks