Add following staff:
1. add a test case in C7_10_LongestValidParethesesTest
2. add the solution of searching element in a rotated sorted array with
duplications.
3. add the solution of connect next node in the same layer when the tree
is not a complete tree
4. a new question of generate a matrix in spiral order:
C4_1A_SpiralMatrixGenerator, as a extention of array rotation