Add a global accessor for getting an instance of the PackageRepository.

Review Request #7731 — Created Oct. 24, 2015 and submitted — Latest diff uploaded

Information

rbpkg
master

Reviewers

This adds a get_repository() function that returns a single instance of
PackageRepository. This allows multiple call sites to share the same
caches.

A method to PackageRepository has also been added to clear out the
caches, which unit tests call to ensure they don't stomp all over each
other.

Unit tests making use of this in an upcoming change pass.