DBMaker: remove circular reference in generics
DBMaker: revert circular reference in generics
SerializerPojo: fix handling of subclassed Enums. See #266
Store: compaction was broken. See #265
Store: rework file release in case of an error while opening. See #264
BTreeMap: add meta-information to each node. In future this could be used for counted btree or per-node aggregations for map-reduce.
Remove unused and long running tests
[maven-release-plugin] prepare release mapdb-0.9.9
[maven-release-plugin] prepare for next development iteration
Site: add 0.9.9 release notes
Site: fix formatting
Examples: fix capitalization typo

otherwise the "Salary sum for all Main Streets" comes back as 0.
BTreeMap: small optimalization in locking method
DBMaker: fix memory leak in shutdown hooks. WSee #272