**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.

*    },
 *    render: function() {...}
 *  });
 *
 * @internal
 */
var ANONYMOUS = '<<anonymous>>';
var ReactPropTypes = {
  array: createPrimitiveTypeChecker('array'),
  bool: createPrimitiveTypeChecker('boolean'),
  func: createPrimitiveTypeChecker('function'),
  number: createPrimitiveTypeChecker('number'),
  object: createPrimitiveTypeChecker('object'),
  string: createPrimitiveTypeChecker('string'),
  symbol: createPrimitiveTypeChecker('symbol'),
  any: createAnyTypeChecker(),
  arrayOf: createArrayOfTypeChecker,
  element: createElementTypeChecker(),
  instanceOf: createInstanceTypeChecker,
  node: createNodeChecker(),
  objectOf: createObjectOfTypeChecker,
  oneOf: createEnumTypeChecker,
  oneOfType: createUnionTypeChecker,
  shape: createShapeTypeChecker,
};
/**
 * inlined Object.is polyfill to avoid requiring consumers ship their own
 * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/is
 */
function is(x, y) {