more contributors;

--- a/doc-src/IsarRef/isar-ref.tex	Wed May 02 21:15:38 2012 +0200
+++ b/doc-src/IsarRef/isar-ref.tex	Wed May 02 21:21:51 2012 +0200
@@ -30,11 +30,13 @@
   Lukas Bulwahn, \\
   Lucas Dixon,
   Florian Haftmann,
-  Gerwin Klein, \\
+  Brian Huffman, \\
+  Gerwin Klein,
   Alexander Krauss,
+  Ond\v{r}ej Kun\v{c}ar, \\
   Tobias Nipkow,
-  Lars Noschinski, \\
-  David von Oheimb,
+  Lars Noschinski,
+  David von Oheimb, \\
   Larry Paulson,
   Sebastian Skalberg
 }