View implements Streamable, but MergeView doesn't. Effect: MergeViews are not correctly marshalled, and only appear as View instances !
This is serious because viewAccepted(View v) callbacks need to know whether v is a View or MergeView ! This bug would always have v be a View, and never a MergeView. This causes incorrect behavior in JBoss Clustering for example.

This works correctly in 2.2.7, and only broke in 2.2.8 because we introduced Streamable in 2.2.8