v1.6.8

Fixed a layout bug with the hands parameter.
Fixed a bug in saving GIFs of patterns with multiple prop types or colors (155).
Reduced memory usage in siteswap generator to avoid out of memory errors on large searches.
Fixed a visual glitch in juggler animation due to drawing order bug.
Fixed internal error caused by empty colors value (148).
Minor UI changes in the siteswap generator input panel.
Moved to Gradle build tool.
Ladder diagram in Visual Editor migrated to Compose (rendering and mouse input).