Marking GraphX as alpha

Author: pwendell

graphx/src/main/scala/org/apache/spark/graphx/package.scala

@@ -19,7 +19,10 @@ package org.apache.spark
 
 import org.apache.spark.util.collection.OpenHashSet
 
-/** GraphX is a graph processing framework built on top of Spark. */
+/**
+ * <span class="badge badge-red" style="float: right;">ALPHA COMPONENT</span>
+ *
+ * GraphX is a graph processing framework built on top of Spark. */
 package object graphx {
   /**
    * A 64-bit vertex identifier that uniquely identifies a vertex within a graph. It does not need