- Change revision type from `qint64` to `size_t` for LMDB in a couple of places (LMDB supports `unsigned int` or `size_t` which are `long unsigned int` on my machine)
- Better support for database flags (duplicate, integer keys, integer values for now but is extensible)
- Main databases' keys are now revisions
- Some databases switched to integer keys databases:
- Main databases
- the revision to uid mapping database
- the revision to entity type mapping database
- Refactor the entity type's `typeDatabases` method (if in the future we need to change the main databases' flags again)
- New uid to revision mapping database (`uidsToRevisions`):
- Stores all revisions (not uid to latest revision) because we need it for cleaning old revisions
- Flags are: duplicates + integer values (so findLatest finds the latest revision for the given uid)
Problems to fix before merging:
- Sometimes Sink can't read what has just been written to the database (maybe because of transactions race conditions)
- Most of the times, this results in Sink not able to find the uid for a given revision by reading the `revisions` database
- `pipelinetest`'s `testModifyWithConflict` fails because the local changes are overriden
The first problem prevents me from running benchmarks