added handling for X11 Forwarding

[bepeit01]

This changes enables X11 Forwarding.
The routines ForwardToRemoteX11 and ForwardToRemote could possibly be merged to on, but i couldn't not test again forwarding, therefore i did not touch it.

[vdombrovski]

Thank you for the contribution @bepeit01 ! Are we the upstream now? 😂

[bepeit01]

No, you are more advanced than upstream ;)
I need the feature from this PR: moul#469 which is open since july and i didn't want to create a PR to a PR...

[vdombrovski]

Yeah about that, I'm not really sure that moul is that active / motivated by the project anymore, there is definitely interest around the project however in the other forks, I know that https://github.com/systemmonkey42/sshportal, and https://github.com/alterway/sshportal are really active and are cherry-picking some of our improvements too, which is great.

Quick note, we're merging our own improvements (which are not always bug fixes, more like modifications) into this fork, and while we're trying to keep them generic, some of them might not suit your needs.

[bepeit01]

Same here... We have a different fork at work where we add our improvements/adaptions as we need it. And i use my fork to add the generic once back to the community,
Actually we have chosen your fork as basis for out internal one because you were one of the most active once and a lot of bugs were already fixed.