Code cleanup

ViewPagerAdapter now has its own file
Async classes are static with WeakReferences to containing entity
History and Today icons are changed
Created new History activity
Modified TasksFragment to determine parent activity (Today, History or else)

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

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context="com.wismna.geoffroy.donext.activities.HistoryActivity">
+    <fragment
+        android:id="@+id/fragment_main"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:name="com.wismna.geoffroy.donext.fragments.MainFragment"
+        />
+</android.support.constraint.ConstraintLayout>

app/src/main/res/menu/menu_main.xml

@@ -13,7 +13,7 @@
         android:orderInCategory="15"
         android:title="@string/action_todayList"
         android:onClick="showTodayList"
-        android:icon="@drawable/ic_stat_name"
+        android:icon="@drawable/ic_today_dark"
         android:visible="false"
         app:showAsAction="ifRoom" />
     <item
@@ -35,7 +35,7 @@
         android:orderInCategory="25"
         android:title="@string/action_history"
         android:onClick="openHistory"
-        android:icon="@drawable/ic_list_white_24dp"
+        android:icon="@drawable/ic_history_dark"
         app:showAsAction="ifRoom" />
     <item
         android:id="@+id/action_settings"

app/src/main/res/values-fr/strings.xml

@@ -61,4 +61,5 @@
     <string name="incompatible_sdk_version">Sorry, your Android version is not supported.</string>
     <string name="action_history">Historique</string>
     <string name="task_list_ok">OK</string>
+    <string name="title_activity_history">Historique</string>
 </resources>

app/src/main/res/values/strings.xml

@@ -20,6 +20,7 @@
     <string name="task_list_confirmation_delete">Delete task list?</string>
     <string name="task_list_drag_handle">Drag handle</string>
     <string name="task_list_no_lists">Create a new task list</string>
+    <string name="task_list_ok">OK</string>
 
     <!-- Strings related to new task dialog -->
     <string name="new_task_list">List</string>
@@ -80,5 +81,7 @@
     <string name="incompatible_sdk_version">Sorry, your Android version is not supported.</string>
     <string name="action_history">History</string>
 
-    <string name="task_list_ok">OK</string>
+    <!-- String related to History -->
+    <string name="title_activity_history">History</string>
+
 </resources>