"optimize" UTF-8 to/from conversions

`time npm test` — before
real	1m18.064s
user	0m47.821s
sys	0m10.795s

`time npm test` — after
real	1m21.550s
user	0m47.743s
sys	0m10.626s

So, um, phooey?
Revert ""optimize" UTF-8 to/from conversions"

This reverts commit 57e046d062c6021d217904cc5d7ac5844bb7bdae.