Use correct XML namespace

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

@@ -1,16 +1,18 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
+      xmlns:app="http://schemas.android.com/apk/res-auto"
       xmlns:tools="http://schemas.android.com/tools"
-    tools:context="org.isoron.uhabits.MainActivity" >
+      tools:context="org.isoron.uhabits.MainActivity">
 
-    <item android:id="@+id/action_show_archived"
-          android:title="@string/show_archived"
+    <item
+        android:id="@+id/action_show_archived"
+        android:checkable="true"
         android:enabled="true"
-          android:checkable="true" />
+        android:title="@string/show_archived"/>
 
     <item
         android:id="@+id/action_settings"
         android:orderInCategory="100"
-        android:showAsAction="never"
-        android:title="@string/action_settings"/>
+        android:title="@string/action_settings"
+        app:showAsAction="never"/>
 
 </menu>

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

@@ -1,9 +1,12 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
+      xmlns:app="http://schemas.android.com/apk/res-auto"
       xmlns:tools="http://schemas.android.com/tools"
-    tools:context="org.isoron.uhabits.MainActivity" >
+      tools:context="org.isoron.uhabits.MainActivity">
 
     <item
         android:id="@+id/action_add"
-        android:title="@string/add_habit" android:showAsAction="always" android:icon="@drawable/ic_action_add"/>
+        android:icon="@drawable/ic_action_add"
+        android:title="@string/add_habit"
+        app:showAsAction="always"/>
 
 </menu>

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

@@ -1,12 +1,12 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
+      xmlns:app="http://schemas.android.com/apk/res-auto"
       xmlns:tools="http://schemas.android.com/tools"
-    tools:context="org.isoron.uhabits.ShowHabitActivity" >
-
+      tools:context="org.isoron.uhabits.ShowHabitActivity">
 
     <item
         android:id="@+id/action_settings"
         android:orderInCategory="100"
-        android:showAsAction="never"
-        android:title="@string/action_settings"/>
+        android:title="@string/action_settings"
+        app:showAsAction="never"/>
 
 </menu>

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

@@ -1,10 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
-<menu xmlns:android="http://schemas.android.com/apk/res/android">
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+      xmlns:app="http://schemas.android.com/apk/res-auto">
 
     <item
         android:id="@+id/action_edit_habit"
-        android:showAsAction="ifRoom"
         android:icon="@drawable/ic_action_edit"
-        android:title="@string/edit"/>
+        android:title="@string/edit"
+        app:showAsAction="ifRoom"/>
 
 </menu>