* rename Model > Mesh, Alembic > SfM
* add checkbox to control Mesh and SfM visibility
* transparentize visibility checkboxes that do not have a direct impact on the current scene (i.e: 'Textures' when the loaded mesh has no texture)
* move 3D content unloading into a contextual submenu
* optional and only available if AlembicEntity QML plugin is in QML import path
* 3D viewer can load a 3D model and an Alembic file at the same time
* add contextual menu options to unload model/Alembic
* cache last loaded image and display it while the main Image is loading to avoid empty screen
* fix the BusyIndicator by dynamically creating a binding on the running property (Qt bug ?)
* remove DiffuseMapMaterial automatically created by the SceneLoader
* use MaterialSwitchers to create and dynamically switch materials on loaded Entities
* add a "Textures" checkbox to perform the toggle
* add DefaultCameraController:
* mouse-only navigation
* keyboard modifiers fallbacks for view re-centering (Ctrl+LeftClick) and fast zooming (Alt+RightClick)
* improved double click handling for 3D Object Picking
* moved logic/Timer to the CameraController
* always use TrianglePicking but only activate the ObjectPicker when necessary
* new footer that displays the number of images / allow to change thumbnail size
* smaller sourceSize for thumbnails (faster to load)
* avoid Nan scales in Viewer2D when no image is loaded
* add Rotation/Scale controls
* add controls to disable default items (grid/locator)
* add drop support to load external 3D models
* add "View All" action in contextual menu to fit to scene
* automatically propose to load the reconstructed mesh when available
* ImageGallery displays images from CameraInit.viewpoints
* support drag&drop of images
* Viewer2D displays and allows basic manipulation of currently selected image
