Cleanup, minor tweaks

- Made some references more type-generic, eliminating a couple imports
- Added logging instead of error stream printing in exception catches
- Made the metadata field sets private
- Fixed some errors in comments
- Reorganzied stuff a bit
add schema for metadata table, update tool
Add Index.update method

Added update method on Index interface, stub implementation on
FusionIndex
Merge branch 'AikumaCloudStorage' into restructure_tables
Change DB table layout

- Moved to wide-row, one per identifier layout.
- Added a JSON version of the schema to git (probably shouldn't live in
the source tree where it is).
- added a method on IndexTool to create the index
- updated FusionIndex to operate on new structure
minor tweaks
Merge branch 'restructure_tables'

Changes table structure to single row