* 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.
Tango: Added Append Mode option (only start a new map after being localized, default true) and the old map is still shown for convenience until localization. Increased minInliers to 25. Increased ICP correspondenceRatio to 0.5. Decreased time to open a database. Saving doesn't close the database anymore and overwrite only if we save with the same name. Removed ICP refining from standard optimization.
