Unversioned metadata support in storage modules.
Initial REST and API metadata support
Fixes for bad-commit requests
Fixes for metadata support
py:  Node#(last_)checkin support
py: bugfixes; classic ts format
rb:  support for Node#(last_)checkin
py:  added Node#getConfig with options
rb:  added Node#getConfig with options
Merge branch 'feature/unversioned-metadata' into develop

Includes database and API support for storing and accessing
arbitrary JSON metadata.  Also builds some client library functionality
atop this, e.g., Node#checkin and Node#last_checkin.  Includes other
client library enhancements as well.