This moves the equivalence hashing code from
algorithm/predicates/utils.go to core/equivalence_cache.go.
In the process, making the hashing function and hashing function factory
both injectable dependencies is removed.
This moves plugin/pkg/scheduler to pkg/scheduler and
plugin/cmd/kube-scheduler to cmd/kube-scheduler.
Bulk of the work was done with gomvpkg, except for kube-scheduler main
package.
