Reimplemented TokuFTEngine using KVDictionary.

Also started using the ftcxx library.
Merge branch 'kv_dictionary' of https://github.com/leifwalsh/mongo into kv_dictionary
fixed typo
improved interface of KVDictionary, implemented get, insert, remove
Hook the KVSortedDataImpl and KVRecordStore into their appropriate test
harnesses, add a default heap dictionary implementation, but it is
probably broken and still needs to be plugged into a KVDictionary test
harness, which is to come
Merge branch 'kv_dictionary' of https://github.com/leifwalsh/mongo into kv_dictionary
compilation fixes
Merge branch 'kv_dictionary' of https://github.com/leifwalsh/mongo into kv_dictionary
improved KVDictionary::Slice and usage
Merge branch 'kv_dictionary' of https://github.com/leifwalsh/mongo into kv_dictionary
replaced bare usage of boost::shared_array
fanciness
dictionary test harness
Merge branch 'kv_dictionary' of https://github.com/leifwalsh/mongo into kv_dictionary
Fix up tests, add default cursor/iter impls that do nothing so no tests
crash