Merge: Ropes

Merge: Ropes

Here they are, after a few months hiding in the fiery depths of the dumpster™, they return, once more.

The Ropes are back, and they're looking for trouble.

On a more serious note, they look a lot more performing than before, thanks to a wrapper-less structure.

The code is also simpler to read and understand (and there's lots more of documentation, I figured @Morriar would like that).

Finally, you can use Strings in a transparent way, never to create Ropes on your own, now the library does it for you.

Furthermore, `RopeBuffer` pridefully returns with the promises of crushing the `FlatBuffer` when concatenating stuff and resisting a bit more to longer strings.
(NDLR: Single-character modifications will be slow.)

Pull-Request: #829
Reviewed-by: Jean Privat <jean@pryen.org>
Reviewed-by: Alexandre Terrasa <alexandre@moz-code.org>
Reviewed-by: Alexis Laferrière <alexis.laf@xymus.net>