Patch #1309579: wait3 and wait4 were added to the posix module by Chad J. Schroeder.

This was a fair amount of rework of the patch.  Refactored test_fork1 so it
could be reused by the new tests for wait3/4.  Also made them into new style
unittests (derive from unittest.TestCase).
diff --git a/Misc/ACKS b/Misc/ACKS
index 9225031..12983c5 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -536,6 +536,7 @@
 Gregor Schmid
 Ralf Schmitt
 Peter Schneider-Kamp
+Chad J. Schroeder
 Sam Schulenburg
 Stefan Schwarzer
 Dietmar Schwertberger