[MERGE] line-endings support: part 1 of 2: versioned properties

[Alexander Belchenko]

Nicholas, thank you very much for feedback.

I think I should actually split my patch in a series of smaller ones
to simplify review process. In this case CLI UI will be in separate
patch and we all can freely discuss how to polish it.

Currently I'm waiting for any feedback from core dev guys, because I need to know
that my design in general is acceptable.

CLI is secondary thing for me right now.