Made more things private.

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

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

...in/scala/org/apache/spark/graphx/impl/EdgePartition.scala

...a/org/apache/spark/graphx/impl/EdgePartitionBuilder.scala

...c/main/scala/org/apache/spark/graphx/impl/GraphImpl.scala

...ala/org/apache/spark/graphx/impl/MessageToPartition.scala

...a/org/apache/spark/graphx/impl/ReplicatedVertexView.scala

...ain/scala/org/apache/spark/graphx/impl/RoutingTable.scala

...main/scala/org/apache/spark/graphx/impl/Serializers.scala

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