- add -openrc subpackage
- cleanup depends for subpackages
- switch to python3

needed by main/py-tox

needed by py3-openzwave

s390x builds with context and coroutine now so we dont need to exclude
anything.

This version removes a few subtle, but rare bugs. It also makes all
shell scripts completely POSIX-compatible by removing the use of
`local`. It also adds locales, but since Alpine does not have a
replacement for gencat, I can't enable that support. The `-N` option
given to configure.sh turns off locale support.

CVE-2019-1787, CVE-2019-1788, CVE-2019-1789

Fixes #10262