libcapsprovider: support for providers

In order to be part of the CAPS universe a printing provider (or printer driver) needs libcapsprovider to communicate with the CAPS Printing Coordinator.

This library provides an API to register the printing provider instance and receive print jobs.

This library is part of the CAPS Printing Coordinator.

If you want to use libcapsprovider in your printer driver, refer Provider API description for details.