Revert "Switch to using raw_utf8"

This reverts commit 2ecb7555a9df1e843fd25f588819e4ca1d94b266.
Revert "JSON Spirit updated to v4.06"

This reverts commit 2227389fa8fa1b9ff19234838fc7b641e935125b.
Merge pull request #3127 from jgarzik/smells-like-json-spirit

Revert recent json-spirit changes