Update sharp

[aptomaKetil]

Update sharp from 0.26.1 to 0.29.1.

Changelog: https://sharp.pixelplumbing.com/changelog

I've had to revert the repository-setting in package.json to lovell/sharp, because they've started using https://www.npmjs.com/package/prebuild-install to download prebuilt binaries, and this lib relies on the repository setting.

Obviously, this is incredibly unmergeable, so I'll just force-push this branch to retain-profile whenever this is approved.

[aptomaKetil]

Probably easier just to look at the commit list. Our three commits are at the top.

https://github.com/aptoma/sharp/commits/update-sharp

[martinj]

I've had to revert the repository-setting in package.json to lovell/sharp, because they've started using https://www.npmjs.com/package/prebuild-install to download prebuilt binaries, and this lib relies on the repository setting.

Does this affect SHARP_DIST_BASE_URL in anyway?

[aptomaKetil]

Checked the install scripts now. SHARP_DIST_BASE_URL is unaffected, however I still need to make some changes. The prebuild-install-script fetches prebuilt binaries for sharp, not libvips. Which means if we leave it to do its business, it'll fetch a prebuilt binary for sharp which does not include our CMYK-fix.

I will undo my change to the repo setting, and use their install scripts to create our own prebuilt binaries instead.

[aptomaKetil]

Reverted the package.json change now.

[aptomaKetil]

Added prebuild command to wiki: https://github.com/aptoma/sharp/wiki