Add 8.7

[jcupitt]

• add an 8.7 dir
• revise dockerfile to remove env vars and set an entrypoint
• revise scripts to use args rather than env vars
• update imagemagick
• move wine test outside container

[jcupitt]

OK, conflicts fixed, and I remove that stray file.

I'm not sure about merging this into my build-win64. I'm still deciding now I feel about MXE. I can see some advantages, but .... uuurk, gnu make.

I'm planning to move all of my vips stuff into the libvips org:

https://github.com/libvips

I've just been too lazy. Perhaps it could go in there?

[kleisauke]

Indeed, MXE has advantages but also its disadvantages. Personally, I find it easier to use than JHBuild and it also seems a bit faster (when I used JHBuild it was constantly rebuilding all dependencies).

Wow, moving all vips stuff into the libvips organization sounds great. I think this repo would fit well there.