root aliases during install should come from the lock file only, for
better reproducibility we don't reuse the value from update for the
following install
Pool construction depends on the install request now, so only required
packages get loaded, add some structure for future asynchronously
loading composer repositories
Breaking change for the plugin interface so bumping the version of
composer-plugin-api to 2.0.0
First step for a refactoring of the package metadata loading mechanism
Jordi Boggiano