Refactored task polling into a single module.
Refactored SWF decision history handling into a dedicated directory.
Add missing GPLv3 license.
Throw out old map/reduce master/slave logic.  New approach will leverages SWF for state tracking.
Re-refactored SWF history code back to a single module.
Syntax for serialize/deserialize structs: to strings (with cast).
Use prelude defined serialization utils.
Get S3 meta data for a single object.
opt-car to optionally get the head of a list.