Add Tiff 300dpi Output

1. Fixed incomplete display when exporting high-resolution bitmaps with JIGplot (caused by the aforementioned multithreading acceleration);
2. Added the export of 300dpi TIFF format images, suitable for publication.

For one-step installers, please download from
https://www.yuque.com/cjchen/hirv8i/iclxpx2841g205hm