Upgrade mercurial to 5.1

This mercurial patch release contains the fix for musl libc so we
can drop the hot patch here.

Add musl libc hotfix to mercurial, bump mercurial to 5.0

Bump pkgrel on mercurial & hg-evolve

mercurial: update to 4.9.1

Add mercurial (shadowing aports until 3.10)