JCBC-431: Config poller for tainted carrier configurations.

This changeset adds a config poller for tainted carrier configurations.
It spawns once it finds a tainted config and stops once its not tainted
anymore.

What a tainted configuration exactly defines, is implemented in each
configuration implementation. The Provider just checks for the field
and acts accordingly.

Change-Id: If4d9c83994ad82b0f22d0ea9edc2bc0e9dca7ffe
Reviewed-on: http://review.couchbase.org/34626
Reviewed-by: Michael Nitschinger <michael.nitschinger@couchbase.com>
Tested-by: Michael Nitschinger <michael.nitschinger@couchbase.com>