Keep logging functionality out of the public API as requested in https://github.com/dlang/dub/pull/2124#issuecomment-813016939.

Fix/Update some tests and make some info messages more similar to original version of Dub

Fix rebase errors

Fix really stupid error in previous commit

Replace --no-colors & --force-colors with --colors={auto|on|off}

Add --force-colors option to force colors enabled

Add --no-colors option to disable colors in terminal ...

Minor: changed function name in logging module

Revert logInfo to print a single line after a fetch

Fixed project upgrade message

Output improvements in package management ...

(dub fetch and dub remove)

Now checks if the output is a console or not ...

This allows to disable colors accordingly, to avoid ASCII escape
sequences in piped output.

!!! tested only on Linux.

Also: minor documentation improvements

Fixed output of some commands ...

Some commands look ugly with the tag-based logging, now using
logInfoNoTag to print "normally" like before.

New logging module - initial functionality ...

The new module replaces dub.internal.vibecompat.core.log by using the
same function names, but implementing colored output and the left
fixed-width tag. Overloaded functions are provided to output colored
text.

Still missing initLogging() and non-TTY stdout/stderr detection

Commandline: Do not duplicate GeneratorSettings fields ...

Instead of adding fields individually to the Command, just store a GeneratorSettings,
and getopt it as needed.

Remove message about system installation of packages ...

This is no longer true, we have /var/lib/dub
Moreover, users should be familiar with this, as it's how most package managers work.

Remove long-deprecated 'install' and 'uninstall' command ...

There were deprecated before dub v1.
I stopped going up the history after 4d8f81b,
on 2013-11-13, where they were already deprecated.

Do not call Project.reinit from commandline ...

reinit is called directly when Project is instantiated. It calls PackageManager.refresh,
which re-reads all packages stored in the package directory.
If we want to make dub smarter and faster, we need to stop scanning all the packages
on disk when we have a resolved dependency tree, and move to a lazy/on-demand approach.
The first step would be to remove this call. See also #2388.

commandline: Catch Exception, not Throwable ...

So that assert errors, which are bugs in dub, get properly reported.

Deprecate once-called redundant getLatestPackage ...

getBestPackage present a more generic interface,
as long as we feed it Dependency.any.

Use Dependency.any whenever possible

Avoid needless string concat in log calls

Fix dub_test_root imports for non-all-at-once compilations (#2288) ...

Which requires a regular `dub_test_root.d` filename *and* adding
the containing directory to the importPaths.

Make `dub describe -c unittest` auto-generate dub_test_root.d if required
Except with `--annotate` for a dry run.

Add a command line option for upgrading all sub packages. ...

Allows to upgrade all path based sub packages of a package, in addition to the package itself, in one go. See also #1245 and #2284.

Allow "dub :subpackage" shortcut syntax to run a certain sub package.

Trivial: Re-use findPackageFile in commandline module

commandline: Refactor and streamline special syntaxes ...

All those special syntaxes only trigger if args.length >= 2,
so first we can nest them in a new scope, which also makes
it visually more distinct.

Additionally, the third and second cases were actually inverted:
if the third case was to pass, it means the second case couldn't
have passed (because they check present/absence of an extension,
respectively), so we can swap them and use an else-if.

The result is arguably much more readable, and highlight the fact
that if the first case (stdin) is used, the second case will.

Add support for coverage at compile-time (CTFE)

Support special test runner configuration for `dub describe` as well

Handle unittest config special case in Dub.generateProject()

Fix #1856 - enable building the special test runner config