Allow iterables to pass node prop type check

[aruberto]

#2376 add support for iterables as children. However if a component adds React.PropTypes.node validation to children, validation fails. This pull request adds an iterable check to ReactPropTypes.isNode()

[jimfb]

lgtm, cc @spicyj

[sophiebits]

We also need to check the values when iteratorFn === propValue.entries.

[camspiers]

I don't completely understand what is going on here, but will this pull values out of generators, thereby meaning they won't have any next values when they are used within the component? Also, how does this deal with infinite iterators?

[aruberto]

Hey @spicyj, I've added scenario for when iteratorFn === propValue.entries

Now checks that value in each key-value pair of an entry iterable is a node.

[jimfb]

ping @spicyj

[jimfb]

Looks good to me, @spicyj's comments have been addressed, no complaints from anyone in almost two weeks, so let's ship it.

[ksmithbaylor]

@camspiers Did you ever get your question addressed? This same scenario came up in #7536, and in doing some research I stumbled upon this PR.