Global ref-database interface for use with Gerrit Code Review.
Enables the de-coupling between Gerrit, its libModules and the different implementations of a globally shared ref-database.
The design for a global ref-db interface can be found as part of the multi-site design documentation, where it first originated and was approved by the community.
In order to consume this library, some Guice bindings need to be registered appropriately. More information in the relevant documentation.