beginning of manifests

This is the beginning of manifests: a representation of all the
relevant state for a server, including its components and all of the
configurable data represented in the models for components.
adding diff util
adding the cluster_diff command, which diffs components
some cruft removal
adding run lists and attribute overrides to round out diff tool
tests for diff tool
fix for realms. can no open clusters back up
fix for realms. can now edit clusters when we open them back up
slight fix to diff colors
cluster diff refactors
cluster diff refactors
stringifying attributes in manifest before comparison