Adds content descriptions to header and avatar buttons in the profile editor and puts the page in a scroll view so it's navigable in landscape mode.

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

@@ -7,9 +7,13 @@
     android:layout_height="match_parent"
     tools:context="com.keylesspalace.tusky.EditProfileActivity">
 
+    <ScrollView
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
         <LinearLayout
             android:layout_width="match_parent"
-        android:layout_height="match_parent"
+            android:layout_height="wrap_content"
             android:orientation="vertical">
 
             <android.support.v7.widget.Toolbar
@@ -37,21 +41,13 @@
                     android:indeterminate="true"
                     android:visibility="gone" />
 
-            <TextView
-                android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
-                android:text="@string/label_header"
-                android:labelFor="@+id/edit_profile_header"
-                android:visibility="gone"/>
-
                 <ImageButton
                     android:layout_width="match_parent"
                     android:layout_height="200dp"
-                android:id="@id/edit_profile_header"
+                    android:id="@+id/edit_profile_header"
                     app:srcCompat="@drawable/ic_add_a_photo_32dp"
-                android:text="@string/action_photo_pick"
-                android:textColor="@color/text_color_primary_dark"
-                android:background="#66000000"/>
+                    android:background="#66000000"
+                    android:contentDescription="@string/label_header" />
             </RelativeLayout>
 
             <RelativeLayout
@@ -74,22 +70,14 @@
                     android:indeterminate="true"
                     android:visibility="gone" />
 
-            <TextView
-                android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
-                android:text="@string/label_avatar"
-                android:labelFor="@+id/edit_profile_avatar"
-                android:visibility="gone"/>
-
                 <ImageButton
                     android:layout_width="80dp"
                     android:layout_height="80dp"
-                android:id="@id/edit_profile_avatar"
+                    android:id="@+id/edit_profile_avatar"
                     app:srcCompat="@drawable/ic_add_a_photo_32dp"
-                android:text="@string/action_photo_pick"
-                android:textColor="@color/text_color_primary_dark"
                     android:elevation="4dp"
-                android:background="@drawable/round_button"/>
+                    android:background="@drawable/round_button"
+                    android:contentDescription="@string/label_avatar" />
             </RelativeLayout>
 
             <android.support.design.widget.TextInputLayout
@@ -129,6 +117,8 @@
 
         </LinearLayout>
 
+    </ScrollView>
+
     <ProgressBar
         android:id="@+id/edit_profile_save_progress"
         android:layout_width="wrap_content"