update Guidebook date

doc/Guidebook.tex

@@ -6,7 +6,6 @@
 %-%% if hyperref isn't available, we can get by with this instead
 %-%%\RequirePackage[errorshow]{tracefnt} \DeclareSymbolFont{typewriter}{OT1}{cmtt}{m}{n}
 %-%\usepackage{longtable}
-\usepackage[T1]{fontenc} 
 \textheight 220mm
 \textwidth 160mm
 \oddsidemargin 0mm
@@ -46,7 +45,7 @@
 %.au
 \author{Original version - Eric S. Raymond\\
 (Edited and expanded for 3.6 by Mike Stephenson and others)}
-\date{June 1, 2015}
+\date{June 21, 2015}
 
 \maketitle