3D viewer: fix bug in Three.js' combined camera
3D viewer: move camera on mouse wheel use instead of zoom

Moving the camera lets one move around more freely and doesn't introduce
perspective distortion.
WebGLApplication: Added option to switch camera to orthographic mode
WebGLApplication: mouse wheel in orthomode to zoom
3D viewer: make far clipping more distant as well as near clipping for ortho cam
3D viewer: remove unneeded update methods for orthographic mode
3D viewer: include zoom in view bookmarks

This is needed for orthographic mode.
3D viewer: update camera projection matrix after view selection

This is needed to trigger a proper update of a selected view in
orthographic mode.
Merge branch 'orthocamera'