Document O(n) operations.

Since most of these methods override an interface or superclass, we have to
put the documentation in the class documentation.
Merge branch 'upstream'
Add bindings for some primitive values.
Use Byte.SIZE not a magic number.
Bump leveldb version to latest release
[maven-release-plugin] prepare release leveldb-mapapi-0.0.1
[maven-release-plugin] prepare for next development iteration