* Fix include
why:
Eth67 not default yet so that got missed
* Rename `LeafKey` => `LeafTie`
why:
Name is a pen picture of what this object is for. Also, it avoids the
ubiquitous term `key`.
* Provided `getOrVoid()` wrapper for `getOrDefault()`
also:
Provide `isValid()` syntactic sugar for `.isNil.not`, `!= 0` etc.
Reorg descriptor source, split into sub-sources
* Bundled `NodeKey` objects with root ID and called it `HashLabel`
why:
`NodeKey` (aka repurposed Hash265) objects are unique only within a
particular sub-trie (e.g. storage slots) which are kept separated
(i.e non-interleaved) by design. This is not applied to the backend
as the map VertexID->NodeKey labelling the nodes needs not be injective.
For the in-memory database (transaction) layers, the injective map
VertexID->(VertexID,NodeKey) is used where the first field of the image
tuple is the root ID of the sub-trie the `NodeKey` object is valid. So
identical storage tries for different accounts can be represented.
* Experimental MP-trie
why:
Deleting records is a infeasible with the current structure
* Added vertex ID recycling management
Todo:
Provide some unit tests
* DB layout update
why:
Main news is the separation of `Merkel` hashes into an extra table.
details:
The code fragments cover conversion between compact MPT records and
Aristo DB records as well as some rudimentary cache handling for
the `Merkel` hashes (i.e. the extra table entries.)
todo:
Add some simple unit test for the descriptor record (currently used
for vertex ID management, only.)
* Updated vertex ID recycling management
details:
added simple unit tests (mainly testing ABI)
* docu update