Don't let a user accidentally exit the setup wizard if they chose to use it

TODO

@@ -6,7 +6,6 @@ Fixes:
 -- Show full network error? Make it copy-able?
 
 Tasks:
-- Add a "do you want to skip tutorial" dialog to back button
 - More layouts for intro and setup (tune for each screen size)
 - Create and bundle better network status icons
 - Subclass EmailListFragment for each default mailbox

app/src/main/java/i2p/bote/android/intro/SetupActivity.java

@@ -7,6 +7,7 @@ import android.support.v7.app.ActionBarActivity;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.Toast;
 
 import i2p.bote.android.R;
 import i2p.bote.android.config.EditIdentityActivity;
@@ -18,6 +19,12 @@ public class SetupActivity extends ActionBarActivity {
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_setup);
+
+        // If a user has chosen to enter the setup wizard, don't let them
+        // accidentally exit it early.
+        getSupportActionBar().setDisplayHomeAsUpEnabled(false);
+        getSupportActionBar().setHomeButtonEnabled(false);
+
         if (savedInstanceState == null) {
             getSupportFragmentManager().beginTransaction()
                     .add(R.id.container, new SetPasswordFragment())
@@ -25,6 +32,13 @@ public class SetupActivity extends ActionBarActivity {
         }
     }
 
+    @Override
+    public void onBackPressed() {
+        // If a user has chosen to enter the setup wizard, don't let them
+        // accidentally exit it early.
+        Toast.makeText(this, R.string.please_finish_setup, Toast.LENGTH_SHORT).show();
+    }
+
 
     /**
      * Set password.