Set the `PhutilLibraryMapBuilder` to be quiet by default

Summary: Most of the cases in which `PhutilLibraryMapBuilder` would be used, it is likely that quiet mode would be desired. The only real exception is `./scripts/phutil_rebuild_map.php`.

Test Plan: Ran `./scripts/phutil_rebuild_map.php src` and `./scripts/phutil_rebuild_map.php --quiet src`.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9860