add solution to Problem 3 in pset 5.

Included are the following 2 files:

	Assignments/Problem_Set-5/ps5/src/factors/engine/PrimeFactorsEngine.java
	Assignments/Problem_Set-5/ps5/src/factors/engine/PrimeFactorsEngineTest.java

Thank you!
							Lawrence X. Amlord
							  Nov. 28th, 2014
							   Xi'an, China