common.js: pair - create a k-v pair
common.js: array - create an array from object array (shorthand to slice)
entangle.flow: remove initiator definition interface
entangle.pick: pick value to top-level
entangle: remove runtime status object

storing status with function closure gets more extensibility
entangle.collect: transform array to object
entangle.core: change function signatures
entangle.sponge: context cacher
entangle.fold: fold
entangle.hash: iterate same data over different converter
entangle.fork: iterate different item on different converter instance