[FEATURE] Remove Apache-2.0 only transitive dependency blocking use in GPL2 projects

[electricbrass]

Is your feature request related to a problem? Please describe.
I was planning on licensing my project using Cursive as GPL2 or later, to match other projects under the same organization, but after setting up cargo deny, I realized that despite being licensed under the MIT license, I can't actually use Cursive due to its dependency on xi_unicode.

Describe the solution you'd like
Drop the xi_unicode dependency and just use unicode_segmentation and unicode_width to implement ChunkIterator

Additional context
Totally understand if this is not something you want to do. If you're okay with this change, I may try doing it myself.

[gyscos]

Hi, and thanks for the report!

Indeed, I hadn't thought of the different license for this, that's unfortunate.

It looks like xi-unicode has not been updated in a while. Not that it needs to, it's a pretty (old) stable logic that doesn't need to change.

I don't currently have the time to re-implement the line break iterator, but if you happen to write a MIT-licensed crate that provides the same feature (or if you contribute it to cursive), then we should be able to drop that dependency.