dev-python/m2crypto: new version upstream

dev-python/m2crypto: new version upstream

There is already a bug 651726, but no activity (>10weeks).
* drop support for libressl, feel free to include again (need patch
rediff or submission upstream, see bug 651726)
* upstream adds python3 support, so include
* update dependencies (swig and openssl)

Amendig per @juippis review:

* Header fixed
* EAPI=7
* openssl: depend on :0 slot without version
* swig: depend on available in portage version (unslotted)
* keeping KEYWORDS as they were from 0.27.0-r2
* adding python3_7, so -> python3_{4..7}

Amending per @a17r review:
* Remove ${PN} from DESCRIPTION

Closes: https://bugs.gentoo.org/651726
Signed-off-by: Kalin KOZHUHAROV <kalin@thinrope.net>
Closes: https://github.com/gentoo/gentoo/pull/10628
Signed-off-by: Andreas Sturmlechner <asturm@gentoo.org>