When using --verbose, always print ::repository in list of packages for installation.

--verbose-main-repo-display option is no longer supported.
3 calls to deprecated portage.repository.config.RepoConfigLoader.mainRepo() function
have been deleted.
Blacklist _ variable.
emerge --info: Modernize output of configuration of repositories.

- Always print detailed configuration of repositories.
- Always skip PORTAGE_REPOSITORIES variable.
- Always skip deprecated PORTDIR, PORTDIR_OVERLAY and SYNC variables.
emerge --info: Always print ::repository.

1 call to deprecated portage.repository.config.RepoConfigLoader.mainRepo() function
has been deleted.
emerge --verbose --quiet-repo-display: Delete deprecated code.

Use portage.repository.config.RepoConfigLoader.__iter__() instead of deprecated
PORTDIR and PORTDIR_OVERLAY.
1 call to deprecated portage.repository.config.RepoConfigLoader.mainRepoLocation()
function has been deleted.