Update v1.2: Material groups now included in mesh exports!

Version 1.2 includes materials when exporting meshes to OBJ! Mesh Exporter now includes material groups! Note: OBJ material file includes material reference and colors, but textures are not included at the moment. Also: - Added prompt to save scene when closing the application. - Minor UI updates. - Camera movement speed can be adjusted from the settings menu. Bug squashed: Couldn't confirm or save while renaming an object.