change EvaluateRPN introducing command pattern for math operators
Revert "change EvaluateRPN introducing command pattern for math operators"

This reverts commit c2fa4cd586fc3c9f42b45a0cb0701a0caded1bbb.

	modified:   src/main/java/EvaluateRPN.java
	deleted:    src/main/java/InsertionSortList.java
change EvaluateRPN introducing command pattern for math operators