Unicode word segmentation for command-line tool

[PanderMusubi]

Please, offer Unicode word segmentation for command-line tool like Nuspell is doing. Only requires Boost Locale, which you already need when building with Nuspell provider.

[rrthomas]

[Copied text from @PanderMusubi]

The Nuspell command-line tool offers Unicode segmentation of text to
words; see
https://github.com/nuspell/nuspell/blob/master/src/nuspell/main.cxx#L283

The result is much much better [t]han simply whitespace segmentation. You
can see the difference with this test
https://github.com/nuspell/misc-nuspell/tree/master/segmentation