changed Value field to unexported and created a Value() method
on each dynOpts type that contains logic to create a rsparser
in case the value field a configuration starts with prefix "~"
otherwise it will return the specified value
Add StorDB to config and services.
Put back the store_cdrs option under cdrs and update the CDRs
service to depend on StorDB.
Define the StorDB interface and add a constructor for it.
Add a constructor for postgres storage.
Add a config sanity check to validate SSL modes for postgres.
Update cgr-engine to consider StorDB on startup.