DOC: add docstrings to the StorageManager
DOC: add docstrings to JSONObjectStore
API: privatize decoder_object_hook()
DOC: add docstrings to Blob
DOC: add docstrings to YAMLObjectStore
DOC: add docstrings to HDF5ObjectStore
DOC: add docstrings to the default storage adapters
STY: cleanup imports in demo storage adapter modules
MNT: remove slightly misleading comment about copyright