Merge changes from master since last sync

commit 81d28cdbb9ea9f128658754a7ca008f3949ea070
Author: Alejandro R. Mosteo <amosteo@unizar.es>
Date:   Wed Sep 15 17:50:45 2021 +0200

    Fix regression in migration to CLIC.Config

commit ede072fcfe0a44e2f09e5ecc5272c29cb7120ad5
Merge: 7e01a362 ff02df63
Author: Alejandro R. Mosteo <amosteo@unizar.es>
Date:   Wed Sep 15 17:22:44 2021 +0200

    Merge #847

commit 7e01a3627f52820251249161bc2af86f904bd393
Merge: d9b14be6 b9239853
Author: Alejandro R. Mosteo <amosteo@unizar.es>
Date:   Wed Sep 15 17:19:42 2021 +0200

    Merge #848

commit d9b14be69af23313974051bc9a7bbf5fbd29ac80
Merge: 74a40736 954135ad
Author: Alejandro R. Mosteo <amosteo@unizar.es>
Date:   Wed Sep 15 17:18:31 2021 +0200

    Merge #846

commit 74a4073606843f18798503444f5f0a058e347e36
Merge: cb50222d b86d79dc
Author: Alejandro R. Mosteo <amosteo@unizar.es>
Date:   Wed Sep 15 17:09:24 2021 +0200

    Merge #844

commit cb50222dfa01774a256dc91d6256dc92fb595e88
Merge: 4c86b8d8 e921ea3b
Author: Alejandro R. Mosteo <amosteo@unizar.es>
Date:   Wed Sep 15 17:08:53 2021 +0200

    Merge #845

commit ff02df63
Author: Alejandro R Mosteo <alejandro@mosteo.com>
Date:   Wed Sep 15 13:44:03 2021 +0200

    New On_Demand action type (#847)

    * New On_Demand action for future-proofing

    * Test for on-demand actions

commit b9239853
Author: Fabien Chouteau <Fabien-Chouteau@users.noreply.github.com>
Date:   Tue Sep 14 15:58:16 2021 +0200

    Alire.Config.Edit: fix for --config with relative path (#848)

commit 954135ad
Author: Alejandro R Mosteo <alejandro@mosteo.com>
Date:   Tue Sep 14 10:04:43 2021 +0200

    Checks on compatibility of tools given via `--select <release>` (#846)

    * Don't present incompatible tools in the assistant

    * Sort gnats by version in the assistant

    Rather than by name

    * Detect origin conflicts in `alr toolchain --select <>`

    * Use already configured tool origin as filter

    * New test for checks on --select <releases>

    * Self-review tweaks

commit b86d79dc
Author: Alejandro R Mosteo <alejandro@mosteo.com>
Date:   Tue Sep 14 10:03:54 2021 +0200

    Don't present incompatible tools in the assistant (#844)

commit e921ea3b
Author: Alejandro R Mosteo <alejandro@mosteo.com>
Date:   Tue Sep 14 10:00:38 2021 +0200

    Sort GNATs by version in the assistant (#845)

    Rather than by name