Make sure devshim does Jackson serialization in a separate classloader

[dpp]

There could be "dev time" vs. "production time" issues with
the way Jackson does serialization. Figure a way to separate
the serialization activities to a classloader that cannot see
the main code.

[tmarble]

Wonder if we could benefit from the boot-clj "pod" infrastructure: https://github.com/boot-clj/boot/wiki/Pods

FFI: http://blog.cognitect.com/cognicast/111