Merge remote-tracking branch 'upstream/stable' into merge_stable

update version to v1.31.0

Fix typo in subpackage license warning

reduce dependency on the working directory ...

Improves library API usage and bugs with the build generator

fix cyclic dependency of dub.internal.utils

Merge remote-tracking branch 'upstream/stable' into merge_stable

update version to v1.31.0-rc.1

replace std.variant with std.sumtype (#2550) ...

Variant is quite big and runtime heavy, with sumtype we already cover
wrong type cases at compile time.

Don't assume the cache path is relative to CWD ...

It is no longer in `$PACKAGE_ROOT/.dub`, but in a central location.

Fix various DDOC warnings

Remove GeneratorSettings.direct as it is never set

Merge pull request #2555 from ibuclaw/merge_stable ...

update version to v1.31.0-beta.1

Implement --color=auto|always|never, fix #2410 (#2552) ...

* Implement --color=auto|always|never, fix #2410

Also improves error message output for unsupported --color values.

* fix compile error with certain D versions

update version to v1.31.0-beta.1

Reduce dependency on `std.file` (#2547)

Use a central build cache for all build artifacts ...

Currently the central build cache is not configurable,
but as most build artifacts end up in `~/.dub/packages/` anyway,
this will be a positive change for users.

Rename UserConfiguration to Settings ...

The latter is more accurate, as we can have system settings
of type UserConfiguration.
This is also a push towards more consistent naming within dub,
as configuration is primarily used for package recipe 'configuration' field.

Move user settings to dub.data.settings ...

By moving it to its own module, we can ensure it's almost a leaf module.
We can also extend unittests to check different scenarios
without relying on integration test.

Move computeBuildID outside of BuildGenerator ...

It does not use anything from 'this', only its input parameters.
Additionally, change the order so it is usable with UFCS.

Rename localRepository to userPackages ...

The 'repository' terminology is confusing, and needs to be interpreted
from the PoV of the PackageManager to make sense. It is likely that
a naive read of this name would lead one to think of git repository,
as opposed to the repository where packages are stored.

Fixed dub init docs (#2537)

Improve dub init custom template docs

Revert "Remove Vibe.d HTTP support / library-nonet" ...

This reverts commit db49cbe.

Add nothrow attributes to dub.semver module

Replace all instances of mkdirRecurse with ensureDir ...

All usages actually want to ensure the directory is present,
and don't care about having a separation between existence check
and creation.

Merge remote-tracking branch 'upstream/stable' into merge_stable

update version to v1.30.0

Merge pull request #2526 from dlang/add_path_workflow ...

Fix add-path based development workflow

Fix version match rules for add-path based packages.

Move foreign code from global scope to dub.internal. ...

Avoids conflicting with the actual dub packages when working with dub as a library. Also, even if just by convention, it ensures that dependent code doesn't rely on this code as a public API.