add support for osc 8 escape code

[tlinford]

This adds support for osc8, for a quick idea of how it works see: https://iterm2.com/documentation-escape-codes.html, while this gist has a lot more details covered.

The case of a newline immediately after a link ends, for example

printf '\e]8;;\n\nhttp/example.com\e\\LINK1\e]8;;\e\\\n

was a bit problematic, since the line gets padded with empty characters up to the width of the row:

I handled this by adding a zero width null character to end the link in this situation, not quite sure if that's a reasonable solution though.

[imsnif]

Hey @tlinford - what's the status of this?

[tlinford]

Hey, I think it's pretty much good to go, want me to go ahead and merge?

[imsnif]

Sure, if you think it's good then go for it.