New Python samples

• FBPlotPopup.py: demonstrates the use of the FBPlotPopup, newly exposed in this release.
• AnimationLayers.py: shows how to create new animation layers and how to animate a cube on different layers.
• FBFbxOptions.py: shows how to create and modify FBFbxOptions to customize the load/save process.
• ActionScriptMgr.py: shows editing of ActionScript.txt that maps a Python action to a script.
• KeyboardMapper.py: shows editing of keyboard mapping files.
• CameraSwitcher.py: demonstrates the use of FBCameraSwitcher.
• CopyAnimation.py: copies the animation data of a model.
• GeometryInstancing.py: demonstrates simple geometry creation and gemoetry instancing.
• ShapeCreation.py: demonstrates basic use of FBGeometry.
• LayeredTexture.py: demonstrates the use of FBLayeredTexture to create and work with a layer.
• TextureAnimation.py and MaterialAndTexture.py: demonstrate the use of material and texture.
• FBGetSelectedModels.py: demonstrates the use of FBGetSelectedModels.
• FBKeyingGroupLocal.py: shows how to create a cube and add translation, rotation and scaling properties of the cube into a custom keying group.
• FBMenu.py: shows how to insert and modify menus, and how to create a pop-up menu.
• FBPlotPopup.py: how to create a plot popup with FBPlotPopup.