'git mv' rst resources to md

This is mainly intended to keep the git history as neat as possible.
No actual conversion yet, so now both the rst and the paradox docs
are broken, which will be fixed in the next commits.

akka-docs/src/main/paradox/java/code/jdocs/ddata/TwoPhaseSet.java

@@ -0,0 +1,48 @@
+/**
+ * Copyright (C) 2015-2017 Lightbend Inc. <http://www.lightbend.com>
+ */
+package jdocs.ddata;
+
+import java.util.HashSet;
+
+import java.util.Set;
+
+import akka.cluster.ddata.AbstractReplicatedData;
+import akka.cluster.ddata.GSet;
+
+//#twophaseset
+public class TwoPhaseSet extends AbstractReplicatedData<TwoPhaseSet> {
+  
+  public final GSet<String> adds;
+  public final GSet<String> removals;
+  
+  public TwoPhaseSet(GSet<String> adds, GSet<String> removals) {
+    this.adds = adds;
+    this.removals = removals;
+  }
+  
+  public static TwoPhaseSet create() {
+    return new TwoPhaseSet(GSet.create(), GSet.create());
+  }
+
+  public TwoPhaseSet add(String element) {
+    return new TwoPhaseSet(adds.add(element), removals);
+  }
+  
+  public TwoPhaseSet remove(String element) {
+    return new TwoPhaseSet(adds, removals.add(element));
+  }
+
+  public Set<String> getElements() {
+    Set<String> result = new HashSet<>(adds.getElements());
+    result.removeAll(removals.getElements());
+    return result;
+  }
+
+  @Override
+  public TwoPhaseSet mergeData(TwoPhaseSet that) {
+    return new TwoPhaseSet(this.adds.merge(that.adds), 
+        this.removals.merge(that.removals));
+  }
+}
+//#twophaseset