Tab customization & direct messages tab (#1012)

* custom tabs

* custom tabs interface

* implement custom tab functionality

* add database migration

* fix bugs, improve ThemeUtils nullability handling

* implement conversationsfragment

* setup ConversationViewHolder

* implement favs

* add button functionality

* revert 10.json

* revert item_status_notification.xml

* implement more menu, replying, fix stuff, clean up

* fix tests

* fix bug with expanding statuses

* min and max number of tabs

* settings support, fix bugs

* database migration

* fix scrolling to top after refresh

* fix                                 bugs

* fix warning in item_conversation

app/src/main/res/layout/item_status_placeholder.xml

@@ -13,7 +13,7 @@
         android:textSize="?attr/status_text_medium" />
 
     <ProgressBar
-        android:id="@+id/progress_bar"
+        android:id="@+id/progressBar"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_gravity="center"