pkg.m: Install local packages in version dependent path (bug #58299). * scripts/pkg/pkg.m: Store local package list in (platform-specific) version dependent path. * scripts/pkg/private/default_prefix.m: Change the default local package installation location to a (platform-specific) version dependent path. * doc/interpreter/package.txi: Adapt documentation. * scripts/pkg/private/install.m: Create directory for local package list if it doesn't exist yet. * libinterp/corefcn/toplev.cc (__octave_config_info__): Add OCTAVE_MAJOR_VERSION, OCTAVE_MINOR_VERSION, and OCTAVE_PATCH_VERSION to output. * libinterp/corefcn/defaults.cc (Fuser_config_dir, Fuser_data_dir): Add new functions to query platform-specific path for user data and user configuration files. * doc/interpreter/system.txi: Add docstrings of new functions to manual.

--- a/scripts/pkg/private/install.m	Mon Mar 22 21:09:04 2021 +1100
+++ b/scripts/pkg/private/install.m	Sun Mar 21 18:10:14 2021 +0100
@@ -282,6 +282,11 @@
       if (ispc)
         local_packages = standardize_paths (local_packages);
       endif
+      if (! exist (fileparts (local_list), "dir")
+          && ! mkdir (fileparts (local_list)))
+        error ("Octave:pkg:install:local-dir", ...
+               "pkg: Could not create directory for local package configuration");
+      endif
       save (local_list, "local_packages");
       installed_pkgs_lst = {local_packages{:}, global_packages{:}};
     endif