Adding a new declarative configuration file to the daqd

Adding a new configuration path that uses a declarative specification instead of an imperative configuration. The config will be based around a standard file format (yaml as it is a little more human friendly than json).

The idea is that the config should be able to setup ordering and dependencies of components to run them correctly. The sysadmin need only specify the leaf functions (write raw frames) and the system knows to start the main thread, producer, ... Also make things order independent to make it easier to sort/compare config files.

This makes the default config file /etc/advligorts/daqd.yaml. The daqd will still parse daqdrc files. To change the config file that is read, use the -c option. If the file ends with a .yaml extension a declarative config file is read, otherwise a daqd.