**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.

}
    var propValue = props[propName];
    var propType = getPropType(propValue);
    if (propType !== 'object') {
      var locationName = ReactPropTypeLocationNames[location];
      return new Error(
        `Invalid ${locationName} \`${propFullName}\` of type ` +
        `\`${propType}\` supplied to \`${componentName}\`, expected an object.`
      );
    }
    for (var key in propValue) {
      if (propValue.hasOwnProperty(key)) {
        var error = typeChecker(
          propValue,
          key,
          componentName,
          location,
          `${propFullName}.${key}`,
          ReactPropTypesSecret
        );
        if (error instanceof Error) {
          return error;
        }
      }
    }
    return null;
  }
  return createChainableTypeChecker(validate);
}
function createUnionTypeChecker(arrayOfTypeCheckers) {