**Do you want to request a _feature_ or report a _bug_?**
Enhancement

**What is the current behavior?**
Element type checker is not as informative as the other ones.

**What is the expected behavior?**
It would be nice to provide the actual type of the prop passed similarly to other type checkers. I.e., instead of 

> Invalid prop `Prop` supplied to `Component`, expected a single ReactElement.

say

> Invalid prop `Prop` of type `type` supplied to `Component`, expected a single ReactElement.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
Seeing this on 15.2.1 but I think it's also applicable to previous versions.

I know the general intention is to move away from prop types, but if there isn't a specific reason for the current behavior I can look into making this more pretty.

typeCheckFail(PropTypes.node, function() {}, failMessage);
      typeCheckFail(PropTypes.node, {key: function() {}}, failMessage);
      typeCheckFail(PropTypes.node, {key: <div />}, failMessage);
    });
    it('should not warn for valid values', function() {
      spyOn(console, 'error');
      typeCheckPass(PropTypes.node, <div />);
      typeCheckPass(PropTypes.node, false);
      typeCheckPass(PropTypes.node, <MyComponent />);
      typeCheckPass(PropTypes.node, 'Some string');
      typeCheckPass(PropTypes.node, []);
      typeCheckPass(PropTypes.node, [
        123,
        'Some string',
        <div />,
        ['Another string', [456], <span />, <MyComponent />],
        <MyComponent />,
      ]);
      
      var frag = ReactFragment.create;
      typeCheckPass(PropTypes.node, frag({
        k0: 123,
        k1: 'Some string',
        k2: <div />,
        k3: frag({
          k30: <MyComponent />,
          k31: frag({k310: <a />}),
          k32: 'Another string',
        }),
        k4: null,