Update version numbering from 1.6 to 2.0.
diff --git a/Doc/Makefile b/Doc/Makefile
index ee1023c..db88c2c 100644
--- a/Doc/Makefile
+++ b/Doc/Makefile
@@ -61,7 +61,7 @@
 
 # This is the *documentation* release, and is used to construct the file
 # names of the downloadable tarballs.
-RELEASE=1.6a2
+RELEASE=2.0b1
 
 
 # These must be declared phony since there