Add ability to purge config

This patch adds paramters to the api and registry
classes that allows the respective config files to
be purged.

This is needed when running in a configuration that
is contrary to the defaults for the platform packager,
such as rabbitmq on RDO

Change-Id: I9f8664b2098bd41b9a98eac095bfec8493ed1254
Merge "Add ability to purge config"
add parameter for endpoint protocols

This gives the ability to specify https endpoint for
internal and/or admin endpoints.

Change-Id: I1f7d96693a5bc2140041658e77cc7920f9577eac
backport: havana