lib: rework debug init

lib: rework debug init

The debug library allows to register a `debug_set_all` callback which
should enable all debugs in a daemon. This callback is implemented
exactly the same in each daemon. Instead of duplicating the code, rework
the lib to allow registration of each debug type, and implement the
common code only once in the lib.

Signed-off-by: Igor Ryzhov <iryzhov@nfware.com>