main: logging + user + pidfile
change http port for 9489
remove old daemon script
controller starts rest api
really create rest api via flask
add a new LookupService class
use real wsgi server
configure the http app when instantiating the lookup service
plugin_manager: load service extensions
filter enabled services according to config
load services with their own config

not with the whole config
Add a _LookupService class

this class is responsible of doing the search in each directories based on the
given configuration.
Add a source manager to the _LookupService
remove the HTTP interface from the lookup service

the http stuff goes in the view plugins that will use the lookup service
add the plugin configuration loading logic
add a config example in etc/xivo-dird/xivo-dird.yml
make lookups async
remove the columns argument from the execute
move some configuration from the dird conf to the plugin conf
extract 2 functions from _load_all_configs

extracted _list_files and _load_yaml_content