Update CHANGES.md and build.xml for b8 release.

Author: bagnell

Diff for: CHANGES.md

@@ -4,7 +4,7 @@ Change Log
 Beta Releases
 -------------
 
-### b8 - xx/xx/2012
+### b8 - 09/05/2012
 
 * Breaking changes:
     * Materials are now created through a centralized Material class using a JSON schema called [Fabric](https://github.com/AnalyticalGraphicsInc/cesium/wiki/Fabric). For example, change:

Diff for: build.xml

@@ -72,7 +72,7 @@
 	<property name="build.minification" value="false" />
 
 	<!-- Inputs -->
-	<property name="version" value="b7" />
+	<property name="version" value="b8" />
 	<property name="sourceDirectory" location="Source" />
 	<property name="shadersDirectory" location="${sourceDirectory}/Shaders" />
 	<property name="examplesDirectory" location="Examples" />