`unicode` crate availability?

[BurntSushi]

At some point, it looks like all of the character class definitions got migrated out of regex and into a separate unicode crate: http://doc.rust-lang.org/unicode/regex/ --- What are the stability plans for unicode? My guess is that things like PERLD aren't going to be included in the Rust distribution, so we'll need to plan to move forward on that.

[lambda-fairy]

Would it be worth spinning these tables out into a separate unicodedata crate? These tables are quite useful outside of regex, and with unstable stuff being moved out the distribution, crates.io would be the perfect home for them.

[alexcrichton]

Currently there are not plans to distribute or stabilize unicode in the near future, so I believe this functionality will need to be folded back into the regex crate.

[BurntSushi]

We dropped reliance on the unicode crate in 787d812, so this is no longer relevant.