sample.c: 
   Simple example of calling pthread. Must be linked with the option '-pthread'
   under FreeBSD.

play.c: multiple threads all cooperating to compute the sum of the integers
	from 1 to n (uses n threads). This highlights the problem of having
	one thread waiting for others to finish (and doesn't actually include
	any reasonable approach!).


Files:  sample.c, play.c (source code) and Makefile