This change is introduced to tackle the confusion between the
configuration of the Alire commands and operations, and the
configuration of crates.

`alr config` is still available and should work as before with the
exception of a deprecation warning message.

* Remove --[un]install, --install-dir

* Patch tests

* User changes

* review of --install et al. removal

* Fix test broken by new crate hash

* Package to track future features

* Loading metadata and explicit binary

* bug box in case of Program_Error

* Fix optionally appearing address in error location

* alire-errors.ads: typo

* Don't run OS initialization during elaboration

As this makes impossible to tweak such initialization with `alr config`.

* Make msys live inside overriden config path by default

* Better explanation in alr.py

* Fix config loading before Windows builtins

* Reinstate lost style checks

* Explicit style checks and corresponding fixes

* Update the supported values of the os and distribution parameters.

* Use new `distribution-unknown`

---------

Co-authored-by: John Serock <1468970+serock@users.noreply.github.com>

...its variable name which is `distribution`

As this makes impossible to tweak such initialization with `alr config`.

* Intepret environment values as paths

This is the likely intended behavior. Down the road we can have a way to have
literal values in these strings.

* Fixes for Windows brokenness

...on outdated port definitions

When a complete solution is printed (`alr show|with --solve`), the "external"
section is now named "missing" (which is what it actually meant).

When a diff is show that contains missing dependencies, a new section is
appended containing separately all missing dependencies, labeled as such:
```
$ alr -f with hello unobtanium
Requested changes:

   ✓ hello      ^1.0.2 (add)
   ✓ unobtanium *      (add)

Changes to dependency solution:

   New solution is incomplete.
   +        hello      1.0.2 (new)
   Missing:
   +❗      unobtanium *     (new,missing:unknown)
```

* Basis for `build --stop-after`

* Implement build stages

* Test for new feature

* User changes

* Remove `sudo` that isn't available on Windows

* Code review

* s/Build_Stages/Stop_Points/

* Add support for ssh

* Test adding indices and pins using ssh

* On-line test for git-over-ssh indexes

---------

Co-authored-by: Alejandro R. Mosteo <amosteo@unizar.es>

* Alr.Commands.Search: change default behavior to include properties

This patch comes from a comment of a user looking for gnatpp in Alire.
gnatpp is part of the libabalang_tools crate and a 1.x `alr search gnatpp`
returns nothing. The reason that by default only the release name and
descriptions are searched. This is quite a bad user interaction.

Here we change the default behavior to search in all properties of a
release, including tags, executables, website, etc.

We also display the list of properties that match the pattern.

Searching in names and descriptions only is still possible with the
--crates switch.

* Alr.Commands.Search: use a set rather than a vector for matching props

Part of #1137.

* Fix bugs causing spurious diffs on update

Solutions were the same, but some types internally where using pointers instead
of pointed objects for comparison.

WIP

* Don't attempt redundant system package installation

* Inform of pin checkouts/updates as for regular crates

* Ensure created folders remain the same

* Fix testsuite index for deterministic make version

That mv operation fails from time to time for unknown reasons.

* New workflow to check GNAT CE builds

* Fix compilation with CE 2020

* Document binary origins

* Test for explicit binary origin

* Report the system package manager in `alr version`

* Also report distro detection disabling

* Use a separate system deployer in unknown systems

Instead of defaulting to apt.

* Distinguish undetected exec from unknown exec name

* Explicitly check all GCC versions we want

* Remove unneeded `aliased`

* Try to use safer reference

* Workaround for GNAT 13 troubles with expr. funcs.

* Fix test index to use deterministic external gnat version

* Test for automated publishing

This test is dependent on a remote repo (`test-index`) on which a PR is opened
during testing, so we better run this one sporadically and locally, or in a
single selected CI configuration.

* Self-review

* Use `ALIRE_TESTSUITE_*` for testsuite env variables

* fix: tmp dir being defined but not existing

* Improved log message for temp file creation

* Prevent deleting a tmp folder not created by us