4.0.0:
    - update to new level interface (v3.0.0):
        - remove db-stream, add db-keys, db-values and db-pairs
        - change missing key condition to type (exn level not-found) instead of (exn leveldb not-found)
3.0.3:
    - add test-generative as dependency
3.0.2:
    - add missing miscmacros dependency
3.0.1:
    - fixed out of date dependencies in meta file
3.0.0:
    - Re-written using the LevelDB C API
    - All conditions are now of type (exn leveldb)
    - Uses new level egg interface and added db-get/default support
    - db-stream now returns key+value combinations as pairs instead of lists
      eg, (("key" . "value")) instead of (("key" "value"))
    - all write operations now return #<unspecified> instead of #t