Link python*-config into VE (pyenv#460)

Required to build binaries that link against Python.
Carl Meyer, the champion for PEP 0405, has confirmed that there isn't a particular reason why `venv` doesn't do that.

Support a prefix resolved by pyenv-latest as base version (pyenv#446)

Strip -<suffix> when autodetecting shell (pyenv#377)

For example bash-5.1, bash-static.

v1.0.0 (pyenv/pyenv#520)