Beginning of libtextsecure refactor.

1) Break out appropriate components.

2) Switch the incoming pipeline from SendReceiveService to
   the JobManager.

library/src/org/whispersystems/textsecure/api/messages/TextSecureGroup.java

@@ -0,0 +1,58 @@
+package org.whispersystems.textsecure.api.messages;
+
+import org.whispersystems.libaxolotl.util.guava.Optional;
+
+import java.util.List;
+
+public class TextSecureGroup {
+
+  public enum Type {
+    UNKNOWN,
+    UPDATE,
+    DELIVER,
+    QUIT
+  }
+
+  private final byte[]                         groupId;
+  private final Type                           type;
+  private final Optional<String>               name;
+  private final Optional<List<String>>         members;
+  private final Optional<TextSecureAttachment> avatar;
+
+
+  public TextSecureGroup(byte[] groupId) {
+    this(Type.DELIVER, groupId, null, null, null);
+  }
+
+  public TextSecureGroup(Type type, byte[] groupId, String name,
+                         List<String> members,
+                         TextSecureAttachment avatar)
+  {
+    this.type    = type;
+    this.groupId = groupId;
+    this.name    = Optional.fromNullable(name);
+    this.members = Optional.fromNullable(members);
+    this.avatar  = Optional.fromNullable(avatar);
+  }
+
+  public byte[] getGroupId() {
+    return groupId;
+  }
+
+  public Type getType() {
+    return type;
+  }
+
+  public Optional<String> getName() {
+    return name;
+  }
+
+  public Optional<List<String>> getMembers() {
+    return members;
+  }
+
+  public Optional<TextSecureAttachment> getAvatar() {
+    return avatar;
+  }
+
+}