* Do the nested partition thing
* Tidy up touched code
* Add nested partition test project, not fully functional
* Clean up variable names, move path_metadata mutation strictly into snapshot_reconciler
* Remove path_metadata, snapshotting is now pure
* Factor out snapshot metadata storage to fix a missing case
* Pull instance_name out of per_path_metadata, closer to what we need
* Refactor to make metadata make more sense, part one
* All appears to be well
* Cull 'metadata_per_path' in favor of 'instances_per_path'
* Remove SnapshotContext
* InstanceMetadata -> PublicInstanceMetadata in web module
* Build in snapshot testing system for testing... snapshots?
* Remove pretty_assertions to see if it fixes a snapshot comparison bug
* Reintroduce pretty assertions, it's not the cause of inequality
* Fix snapshot tests with custom relative path serializer
