Adrian Shum

Results 4 issues of Adrian Shum

This enables creating new image object directly from file path, using [vips_image_new_from_file](https://www.libvips.org/API/current/VipsImage.html#vips-image-new-from-file): Below is the go bench of `NewImageFromFile` against the master branch. The memory difference `B/op` is very noticeable....

This is a WIP of write stream implementation using [VipsTargetCustom](https://www.libvips.org/API/current/VipsTargetCustom.html). ![Screenshot 2022-08-16 at 10 36 10](https://user-images.githubusercontent.com/293790/184786610-e8ac2401-2f49-489e-b7a9-bd6a4cc5ee0f.png) Using this build, the memory usage of 6 instances exploded then starting to scale...