Tracking: imageops:: and DynImage::crop()/crop_imm() breakage

[nabijaczleweli]

Previously: #1200 (comment)

1. imageops::crop() is to be renamed to crop_mut(), and imageops::crop_imm() to crop()
2. DynImage::crop()'s signature is to be replaced with crop_imm()'s, and crop_imm() removed

[RReverser]

Just noticed that docs of DynamicImage::crop says the signature will be replaced in 0.24 release, but looks like that never happened even though 0.24 was released some time ago? Should the docs be updated? @HeroicKatora

[fintelia]

Yeah, probably should update the docs. Though if anyone is interested in making a PR, we can make note of it in #1943 to make sure they don't get forgotten when we are making the 0.25 release