Iteratee should have less arguments

[YuriGor]

I received good feedback, I agree with. Iteratee should have less arguments, now it's hard to remember right order, also code looks unreadable when last argument needed. value, key, may be source collection will be enough, same as in Lodash. Rest of arguments such as path, depth, parent* should be passed as fields of single object context or properties. It will be breaking change, so I need to think twice.

[YuriGor]

Due to lack of feedback I started discussion in this Lodash issue Welcome anybody, who have anything to say.

[YuriGor]

To mimic native js array methods predicates but still have it usable I decided to have this predicate signature:

(value, key|index, parentValue, context)

where context is an object with fields:

• path - path to current value
• parent - object with the current parent's value, key|index, path, parent
• parents - array with all parent objects from the current to the root. parent object listed above is just the last element of this array
• obj - source object
• depth - current value's nested level

next three fields are available if options.checkCircular was true, otherwise they will be undefined

• isCircular - true if the current value is a circular reference.
• circularParent - parent object from parents array referenced by current value or null if not isCircular.
• circularParentIndex - index of circularParent in the parents array or -1

[YuriGor]

done in v2.0.0