Add original author of setuptools, PJ Eby, to CONTRIBUTORS

--HG--
branch : Setuptools-Distribute merge
extra : source : 9417b02804bcd1f1b316a68860faa3c19f88897c

CONTRIBUTORS.txt

@@ -19,6 +19,7 @@ Contributors
 * Martin von Löwis
 * Noufal Ibrahim
 * Pete Hollobon
+* Philip J. Eby
 * Philip Jenvey
 * Reinout van Rees
 * Robert Myers