Extract a common function for builder.createContainer
Extract imageCache for doing cache probes
Removes the cacheBuested field from Builder
Create a new containerManager class which reduces the interface between the
builder and managing containers to 3 functions (from 6)
Signed-off-by: Daniel Nephin <dnephin@docker.com>
Upstream-commit: 19f3b0715cf89f336efa286ea1d3f8b57d8c4973
Component: engine
850d525b5f