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