Better UX handling on identity key mismatches.

1) Migrate from GSON to Jackson everywhere.

2) Add support for storing identity key conflicts on message rows.

3) Add limited support for surfacing identity key conflicts in UI.

src/org/thoughtcrime/securesms/MessageDetailsRecipientAdapter.java

@@ -0,0 +1,58 @@
+package org.thoughtcrime.securesms;
+
+import android.content.Context;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.AbsListView;
+import android.widget.BaseAdapter;
+
+import org.thoughtcrime.securesms.crypto.MasterSecret;
+import org.thoughtcrime.securesms.database.model.MessageRecord;
+import org.thoughtcrime.securesms.recipients.Recipients;
+
+public class MessageDetailsRecipientAdapter extends BaseAdapter implements AbsListView.RecyclerListener {
+
+  private Context       context;
+  private MasterSecret  masterSecret;
+  private MessageRecord record;
+  private Recipients    recipients;
+
+  public MessageDetailsRecipientAdapter(Context context, MasterSecret masterSecret, MessageRecord record, Recipients recipients) {
+    this.context      = context;
+    this.masterSecret = masterSecret;
+    this.record       = record;
+    this.recipients   = recipients;
+  }
+
+  @Override
+  public int getCount() {
+    return recipients.getRecipientsList().size();
+  }
+
+  @Override
+  public Object getItem(int position) {
+    return recipients.getRecipientsList().get(position);
+  }
+
+  @Override
+  public long getItemId(int position) {
+    return recipients.getRecipientsList().get(position).getRecipientId();
+  }
+
+  @Override
+  public View getView(int position, View convertView, ViewGroup parent) {
+    if (convertView == null) {
+      convertView = LayoutInflater.from(context).inflate(R.layout.message_details_recipient, parent, false);
+    }
+
+    ((MessageRecipientListItem)convertView).set(masterSecret, record, recipients, position);
+    return convertView;
+  }
+
+  @Override
+  public void onMovedToScrapHeap(View view) {
+    ((MessageRecipientListItem)view).unbind();
+  }
+
+}