Add sort, sortrows, median and their unit test.

src/Function2D.h

@@ -64,6 +64,13 @@ namespace Aurora {
      */
     Matrix mean(const Matrix& aMatrix,FunctionDirection direction = Column, bool aIncludeNan = true);
 
+    Matrix sort(const Matrix& aMatrix);
+    Matrix sort(Matrix&& aMatrix);
+
+    Matrix sortrows(const Matrix& aMatrix);
+    Matrix sortrows(Matrix&& aMatrix);
+
+    Matrix median(const Matrix& aMatrix);
 };