This directory can be used to configure Neutron services with custom
user-defined configuration files. To use the facility, just drop a file (or a
symlink) that has .conf file name extension into an appropriate directory to
make a service read it during initialization. 'common' directory is read by all
Neutron services.

Note that user-defined configuration files override any configuration values
defined in other files read by services. Service specific configuration
directories beat common one.