Merge branch 'feature/connection' into develop

Optimization
Cleaning

app/src/main/java/fr/utc/simde/payutc/MainActivity.java

@@ -2,7 +2,6 @@ package fr.utc.simde.payutc;
 
 import android.app.Activity;
 import android.app.ProgressDialog;
-import android.content.Context;
 import android.content.DialogInterface;
 import android.content.SharedPreferences;
 import android.support.v7.app.AlertDialog;
@@ -14,15 +13,9 @@ import android.widget.EditText;
 import android.widget.TextView;
 import android.widget.Toast;
 
-import org.json.JSONException;
-import org.json.JSONObject;
-
 import java.text.SimpleDateFormat;
 import java.util.Date;
-import java.util.HashMap;
-import java.util.Iterator;
 import java.util.Locale;
-import java.util.Map;
 
 import fr.utc.simde.payutc.tools.NFCActivity;
 import fr.utc.simde.payutc.tools.CASConnexion;

app/src/main/java/fr/utc/simde/payutc/tools/CASConnexion.java

 package fr.utc.simde.payutc.tools;
 
-import android.util.Log;
-
 /**
  * Created by Samy on 24/10/2017.
  */

app/src/main/java/fr/utc/simde/payutc/tools/Dialog.java

 package fr.utc.simde.payutc.tools;
 
 import android.app.Activity;
-import android.app.ProgressDialog;
 import android.content.Context;
-import android.support.v7.app.ActionBar;
 import android.support.v7.app.AlertDialog;
-import android.util.Log;
 import android.view.inputmethod.InputMethodManager;
 import android.widget.EditText;
-import android.widget.Toast;
 
-import fr.utc.simde.payutc.MainActivity;
 import fr.utc.simde.payutc.R;
 
 /**