Tango refactoring (#534)

* Created general CameraMobile interface. Tango is now optional. Camera is disabled on visualizaion (battery saving).

* Working android app on non-tango android phones (tested on x86_64 android emulator).

* fixed typo

* android: updated tango not available msg

* android: fixed build with latest android sdk/ndk

* Added ARCore limited support for pose and rgb streams.

* Added AREngine support. Don't assert if depth size is not a modulo of rgb size.

* Added ARCore shared camera support

* android: fixed read/write runtime permissions for >=api23. arcore ndk: added feature point cloud. Fixed file sharing persmissions (>=api24 issue)

* ARCore NDK: mapping with feature point cloud

* android: Added post build strip command to reduce native library size

* android: fixed some compilation issues

* android: put back gtsam as default optimizer, manifest min api is dynamic based on cmake parameters

* AREngine: min api 24

* android: Fixed build without AREngine

* android: fixed not available libraries for API<24

* android: fixed build with old cmake versions

* android: set arcore min api to 23

* android: fixed arengine error on start when not built with native arengine support

* android: fixed tango camera permission for api>=23

* Added bionic android docker files

* Fixed wrong 3D words projection when depth size is not an exact multiple of rgb size. DbViewer: fixed images size not correctly shown in label of the calibration. ImageView: fixed depth scale when depth size is not a multiple of rgb size

* CameraMobile: added exact display rotation for local transform

* DbViewer: fixed gravity link shown in constraint view, show full local transform matrix in camera calibration label

* Android: fixed localization mode in visualization, fixed some tansitions between some UI states

* Android: Hide stop button when HUD is hidden. Updated About years.

app/android/res/layout/activity_rtabmap.xml

@@ -27,6 +27,26 @@
         android:layout_width="wrap_content"
         android:layout_height="match_parent"
         android:fitsSystemWindows="true">
+        
+    <ImageButton
+        android:id="@+id/start_button"
+        android:layout_width="100dp"
+        android:layout_height="wrap_content"
+        android:layout_alignParentBottom="true"
+        android:layout_centerHorizontal="true"
+        android:src="@drawable/start96"
+        android:background="@null"
+        android:layout_marginBottom="10dp" />
+
+    <ImageButton
+        android:id="@+id/stop_button"
+        android:layout_width="100dp"
+        android:layout_height="wrap_content"
+        android:layout_alignParentBottom="true"
+        android:layout_centerHorizontal="true"
+        android:src="@drawable/stop96"
+        android:background="@null"
+        android:layout_marginBottom="10dp" />
     
     <ToggleButton
         android:id="@+id/wireframe_button"
@@ -80,16 +100,6 @@
         android:text="@string/camera_button"
         android:spinnerMode="dropdown"/>
 
-    <ToggleButton
-        android:id="@+id/pause_button"
-        android:layout_width="100dp"
-        android:layout_height="wrap_content"
-		android:layout_marginRight="5dp"
-        android:layout_alignParentTop="true"
-        android:layout_marginTop="10dp"
-        android:layout_alignParentRight="true"
-        android:textOff="@string/pause"
-        android:textOn="@string/resume" />
 
     <Button
         android:id="@+id/button_shareToSketchfab"
@@ -138,7 +148,22 @@
         android:paddingBottom="10dp"
         android:progressDrawable="@drawable/custom_seekbar" />
 
+    <Button
+        android:id="@+id/button_library"
+        android:layout_width="match_parent"
+        android:layout_height="100dp"
+        android:layout_centerHorizontal="true"
+        android:layout_gravity="top"
+        android:layout_marginTop="100dp"
+        android:text="@string/library" />
 
+    <Button
+        android:id="@+id/button_new_scan"
+        android:layout_width="match_parent"
+        android:layout_height="100dp"
+        android:layout_alignLeft="@+id/button_library"
+        android:layout_below="@+id/button_library"
+        android:text="@string/new_scan" />
 
 </RelativeLayout>        
 </RelativeLayout>