Add Philip to AUTHORS.

AUTHORS

@@ -35,7 +35,7 @@ Noriaki Yamazaki, Ben Klopfenstein, Vic Lee, Christian Beier,
 Alexander Dorokhine, Corentin Chary, Wouter Van Meir, George Kiagiadakis,
 Joel Martin, Gernot Tenchio, William Roberts, Cristian Rodríguez,
 George Fleury, Kan-Ru Chen, Steve Guo, Luca Stauble, Peter Watkins,
-Kyle J. McKay and Mateus Cesar Groess.
+Kyle J. McKay, Mateus Cesar Groess and Philip Van Hoof.
 
 Probably I forgot quite a few people sending a patch here and there, which
 really made a difference. Without those, some obscure bugs still would