Implement PuTTY 0.64 connection sharing

Latest PuTTY version supports connection sharing allowing opening multiple sessions (terminal or other) over single connection. This avoids need to do manual authentication. Would be great if WinSCP could support it - this could be used from within any environment without saving passwords. Link to feature:

https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/ssh2-generality.html

Thanks.
I'm aware of the feature. We will consider implementing it.