Implement builtin function EvaluateFunctionPointer()
Add test cases for EvaluateFunctionPointer()
Merge branch 'high_order_function' into StableBranchWithTestcases
Rename EvaluateFunctionPointer() to Evaluate(); add test cases
Add more test cases for Evaluate() function
Merge pull request #157 from ke-yu/StableBranchWithTestcases

Add  function EvaluateFunctionPointer() and test cases.