Add the PopOS wallpapers recipe

See merge request !366

Add the Ubuntu wallpapers recipe

See merge request redox-os/cookbook!365

Add Path variant to SourceRecipe

See merge request redox-os/cookbook!396

Better TODOs for sqlite3.

See merge request redox-os/cookbook!395

Also:
* rustfmt

Fix and clean up the perl5 recipe.

See merge request redox-os/cookbook!393

Remove the -Csoft-float argument when building the kernel

See merge request redox-os/cookbook!392

The targets specify the soft-float ABI already and -Csoft-float should likely
have never existed in the first place. It is unsound to mix crates compiled
with different float ABI's and the only stable way to get all crates to agree
on the soft float ABI is by specifying a target which uses the soft float ABI
anyway even without explicit -Csoft-float.

See also https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/.60-Csoft-float.60.20considered.20harmful

Update GNU make to v4.4 and create new recipe and new patch.

See merge request redox-os/cookbook!390

Make perl5 recipe to build perl 5.40.

See merge request redox-os/cookbook!389

Migrate the book recipe to /usr

See merge request redox-os/cookbook!385

Add the website recipe

See merge request redox-os/cookbook!386

Fix fetch.sh for subdirs

See merge request redox-os/cookbook!387

Document the TODO for working recipes

See merge request redox-os/cookbook!388