add CC(BY-NC-SN) License to solution 13.2-1.

Modified are the following 2 files:

	13.2-1.pdf
	13.2-1.tm

Thank you!
							Lawrence X. Amlord
							  May 8th, 2014
							  Xi'an, China
add solution to Exercise 13.2-2.

Included are the following 2 files:

	13.2-2.pdf
	13.2-2.tm

Thank you!
							Lawrence X. Amlord
							  May 8th, 2014
							  Xi'an, China