Stubbing out Chrome.
Merge branch 'master' into topic/chrome
Start removing the Logger, so I can replace it with Chrome.
More work to move away from Logger.
Big refactor to new Chrome.
A little cleanup in the tester.
Sprinkle in some diagnostic messages.
Remove unused imports.
Warn when skipping a target that is satisfied by perl.
The PrerequisiteFilter is gone.

This is now just implemented as a callback, which can take
advantage of the is_core method on PackageSpec to determine
if a package is in core or not.
Show progress if not showing diagnostic messages.
Hooray! The logger is gone!
mend
More Hooray!  The Configurable role is gone.

Everyone that needs access to the Repo has it.
If you need to get a Config, just get it from the Repo.
Statistics doesn't need a repo anymore -- it gets it from the stack.