(Will only work with Devuan >= 4 (Chimaera) - reason is
that in Devuan < 4, the platform.linux_distribution module is
used to get distro details - and this module is unable to
distinguish between Debian and Devuan. In Chimaera, python3 is 3.9,
and in this, platform.linux_distribution has been removed, so that
distro details are obtained using distro.linux_distribution - which
is able to distinguish between Debian and Devuan)

Details:

- added azurelinuxagent/common/osutil/devuan.py
- modified azurelinuxagent/common/osutil/factory.py to use devuan.py
- added init and config files for devuan
- modified setup.py for devuan support
- modified tests/common/osutil/test_factory.py to test devuan support

… pidfile, and simplified status to reflect this

…d up some comments