Add the new files from the foundationdb branch.
Update to new API and new test method.
Better exception mapping: everything isn't temporary.
Add tracing like BDB.
React to exception class renaming.
Improve logging a little bit.
Locking is done by storage engine: declare so and ignore requests for it.
Use a better name that doesn't conflict for FDB directory, which isn't a file-system directory.
Allow enabling of trace file.
Update to new refactored KV API.