Updated lib/levenshtein: Improved speed, closing #1
Updated lib/levenshtein: Improved speed, closing #1

Thanks to stealing from @andrei-m's implementation
(https://gist.github.com/andrei-m/982927) we gained 140k op/s.

The major bottleneck was not using `charAt` (faster in this case),
even though jsperf tests suggested otherwise.

jhermsmeier/node-speech