Licenses: remove the possibility of custom license text

Part of #191.

As discussed in #191, it is enough to limit the license field to one of
the possible identifier ...

Add handling for recent FSF and Community GNAT releases

Instead, global switches are shown when alr --help alone is used.
A message in each individual c...

`dev --hash` has been moved to `publish --hash`. Also, help points
to an online document with (i...

Add maintainers-logins support

Also make explicit the need for well-formed emails in both
`maintainers` and `maintainers-logins`

Some single-subprogram tests are simpler to do in Ada proper than
through a fully-fledged test c...

Includes adding maintainers-logins to default properties.
These are used when initializing a rel...

Added as part of a new Alire.Properties.Labeled.Validate procedure.
Also added a clearer diagnos...

This index is only used for an `alr search --list`; so it checks that
the default index (usually...

This allows doing a three step deployment:
1. Fetch sources
2. Verify hashes
3. Unpack sources

...

Most of these are remainders of the original index expressions, with
a few remainders of the abs...

This interface was used by types that had to be converted into Ada
code in the original index.

These were used in the original index to ensure compilation of
dependencies of the root crate.

Most things there were only used by the original index crate files.

Do not fail resolution of unavailable native crates, and report these as hints

Formerly, Ada-like notation was used, but this ceased to make sense
once we moved to the TOML in...

- get now shows a warning about missing external native dependencies
- show now lists missing na...

This is still unused; this is a preparation step to make the hints
available in all places in al...

The existing Query_Policies as been renamed to the more precise
Age_Policies, and a new Hint_Pol...

This is done to allow a Filesystem origin to report True/False dep-
ending on its two use cases:...

Add local tarballs as a valid filesystem origin

* Integrity test checks that hashing is taking place
* Unpack test checks that contents are same...

Various minor fixes/feats

Enhance the RAII tmp file type so temporary files can be given a
explicit name instead of a rand...

GNATCOLL exposes some pointers/free operations, I guess to enable use
in restricted runtimes/con...

Developer feature to compute hashes of origins

Currently `alr dev --hash <URL>`. At some point, when we have a
clearer idea of the publishing w...

This is intended to be used for initial hash computation, not to
bypass hash checks on indexed a...

Assorted minor changes

It was actually unneeded.

And add extra checks to avoid mixing these with regular strings.

Indefinite_Holders caused an exception on termination even without
existing references to the ho...

Updated readme to remove obsolete information

Mention that we are ramping up towards public beta so changes to be expected.
Hide the installer...

Generalize integrity checking and implement it for git origins

This way we can test integrity verification of VCSs without needing
internet connectivity.

Using GNAT.OS_Lib.Argument_String_To_List seems to fail on strings
with pipes, so we need a way ...

And refactored Source_Archive to fit in

Being subtypes of string made too easy to mix them up

The verification of downloaded info is generalized for all origins,
and also we allow having mor...

These are not actually running and cause an error in non-debian
docker images.

Fix errors about native packages in unknown platforms.

Fix case insensitivity for crate names

Set up gnatelim for future use