Allow to create/remove categories. Some refactoring.

app/src/main/java/eu/kanade/mangafeed/ui/base/activity/BaseActivity.java

@@ -1,14 +1,27 @@
 package eu.kanade.mangafeed.ui.base.activity;
 
-import android.content.Context;
+import android.os.Bundle;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.Toolbar;
 import android.view.MenuItem;
 
 import de.greenrobot.event.EventBus;
+import icepick.Icepick;
 
 public class BaseActivity extends AppCompatActivity {
 
+    @Override
+    protected void onCreate(Bundle savedState) {
+        super.onCreate(savedState);
+        Icepick.restoreInstanceState(this, savedState);
+    }
+
+    @Override
+    protected void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+        Icepick.saveInstanceState(this, outState);
+    }
+
     protected void setupToolbar(Toolbar toolbar) {
         setSupportActionBar(toolbar);
         if (getSupportActionBar() != null)
@@ -35,10 +48,6 @@ public class BaseActivity extends AppCompatActivity {
             getSupportActionBar().setSubtitle(getString(titleResource));
     }
 
-    public Context getActivity() {
-        return this;
-    }
-
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {