Expand output of rhizome add and import

Rename 'secret:' field to '.secret:' (non-manifest-fields start with '.'
using the same convention as rhizome list)

Add '.author' and 'BK' fields to "rhizome add"

Add 'BK' field to "rhizome import"

Fix 'rhizomeops' tests to assert no 'author' and 'BK' output fields from
"rhizome add" with no author

Fiz testdefs.sh and testdefs_rhizome.sh to support new output fields
Cosmetic changes to whitespace

Make it easier to edit in Vim
Fix "rhizome hash file" command for nil files

Now returns an empty result for zero-length file or zero-length file name

Test framework only invokes on non-zero-length files
Improve comments on Rhizome db functions
Make some Rhizome db functions static
Improve Rhizome debugging

Log the integer result of an int64 query
Refactor rhizome_cleanup()

Compute time horizons once only, not once per query

Factor query that deletes orphan FILEBLOBS rows into its own function
Fix duplicate payload logic

rhizome_finish_write() was treating a duplicate file hash as an error,
instead of dealing with it sensibly
Rename 'rhizomeops' test case

AddDuplicate -> AddDeDuplicate
Improve Rhizome test functions

Options to allow manifest name to be given explicitly to override the
conventional "<filename>.manifest"
Add "rhizome add file" --force-new option

Overrides the default behaviour of de-duplicating added manifests

New 'rhizomeops' test case: AddForceDuplicate