odd version handling

[gyakovlev]

@kentfredric I remember you mentioned some version problems.

looks like this regex solves it
gentoo/gentoo#14287
https://bugs.gentoo.org/705044

[kentfredric]

Only recent versioning problem I recall is upstream using versions like: '0.1.0-alpha.4', which simply cannot be mapped verbatim in Gentoo, as that's an illegal version in Gentoo.

I've had to resort to bodging it and calling it "0.1.0_alpha4" and then using ver-cut inside the ebuild to make it work.

[kentfredric]

( I also suspect the presence of the "-" inside the version part would completely reck those bash substitutions )