PackageManager: Store packages hierarchically, by version ...

As explained in the changelog, this hierarchy makes much more sense
than the current one, and will make it possible to read the version
from the directory name.

Don't depend on the whole of Vibe.d for the test_registry ...

Makes the code a bit more verbose, but remove the dependency to vibe-d:mongodb,
which happens to be the one currently failing on master.

auto-guess CI frontend version ...

To conditionally run tests properly on alpine

Add unittest to test collection of C sources and headers

make build names much smaller (#2589)

Fix #2574: Suggest alternative spelling when a command is mistyped (#2593) ...

Co-authored-by: WebFreak001 <gh@webfreak.org>

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

fix #2587

Make `dub run --root=x` default app CWD in dub CWD ...

Fix #2582

Add betterC support - fixes #1636 (#2581) ...

Co-authored-by: Etienne Cimon <etcimon@gmail.com>
Co-authored-by: WebFreak001 <gh@webfreak.org>

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

Add dub-as-a-lib test case for different CWD

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

tests: Correct recurse in issue1408-inherit-linker-files ...

Otherwise it uses the system's dub which might give unpredictable results.

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.

Add test for add-path based package selection.

[add tests]

Fix #2450 - issue1474 testcase is broken on Windows

Add test

Add test

Posix: Add default SONAME/install_name for dynamic libraries ...

Setting it to the filename (ELF) or `@rpath/<file name>` (Mach-O).

This seems to be required in order to use the libraries copied to
the output directory of dependees - either by setting the
LD_LIBRARY_PATH env var when starting the executable, or baking a
RUNPATH into the executable (e.g., via `patchelf --set-rpath` for
deployment).

Otherwise the loader tries to load the library from the original
location specified in the linking cmdline, which is some
`<path to dep pkg>/.dub/…` path (and apparently potentially
relative, and thus even more brittle). For ELF, I would assume
that all SONAME + DT_NEEDED entries (of executable + all .so libs)
would need to be post-processed to enable loading the libs from the
executable's directory (well, any non-original location).

CI: Update versions of dub for fetch test ...

Those versions are old and broken with the latest compiler,
hence dub run will fail. Use the three most recent versions
(at the time of writing) to solve this issue.

add $DPATH environment variable for file locations (#2281) ...

* error out on unknown environment variables

* add env + config for package + settings locations

fix #229

* adjust to review, extend $DPATH test

* review round 2

Forward flag `--color={on,off}` to compiler calls (#2382) ...

When the user sets the color mode explicitly,
we forward it to the compiler for consistency,
while making sure it doesn't impact the build cache ID.

Fix #2348 Crash when describing postBuildCommands

LDC: Use `-fvisibility=public -dllimport=all` when compiling a Windows DLL (#2412) ...

As `-shared` can only be used when linking the DLL in the same cmdline too.
On Windows, `-shared` changes the defaults of some important settings wrt.
dllim/export, so specify those explicitly when *compiling* a DLL with dub
(or some static lib dependency thereof etc.).

git ignore files generated by scripts/ci/travis.sh and move ignores from .gitignore to test/.gitignore

Rename CLI flag --colors to --color any D code symbols accordingly

improve some output coloring ...

See #2347

Remove a few usages of old version-spec approach from test-suite