Added Berkeley Yacc sources

util/byacc/ACKNOWLEDGEMENTS

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+     Berkeley Yacc owes much to the unflagging efforts of Keith Bostic.
+His badgering kept me working on it long after I was ready to quit.
+
+     Berkeley Yacc is based on the excellent algorithm for computing LALR(1)
+lookaheads developed by Tom Pennello and Frank DeRemer.  The algorithm is
+described in their almost impenetrable article in TOPLAS 4,4.
+
+     Finally, much of the credit for the latest version must go to those
+who pointed out deficiencies of my earlier releases.  Among the most
+prolific contributors were
+
+	  Benson I. Margulies
+	  Dave Gentzel
+	  Antoine Verheijen
+	  Peter S. Housel
+	  Dale Smith
+	  Ozan Yigit
+	  John Campbell
+	  Bill Sommerfeld
+	  Paul Hilfinger
+	  Gary Bridgewater
+	  Dave Bakken
+	  Dan Lanciani
+	  Richard Sargent
+	  Parag Patel