New Exporting Options (1.6.0 Release)

Saving images was limited to 8 bit pixel format which is not suitable for heightmaps. Version 1.6.0 brings you a set of new features for exporting grayscale images and heightmaps. The following are all changes in detail: * The new node "Save Heightmap" features 16 bit exports of grayscale images (heightmaps). It supports three different file formats. * The new node "Tiled Heightmap Export" also supports 16 bit data and works similar to the existing "Tiled Export" for 8 bit rgba images. * Polished all exporting ui widgets for better usability of filename selection. * Demo Version: Downscaling of images during export now preserves the aspect ratio. * Several small bugs related to saving and exporting have been fixed.