Package fsync keeps files and directories in sync.
fork&modify from fsync.
Add Syncer.Output bool:
type Syncer struct {
// Set this to true to delete files in the destination that don't exist
// in the source.
Delete bool
// By default, modification times are synced. This can be turned off by
// setting this to true.
NoTimes bool
// Output each file name during sync.
Output bool
// TODO add options for not checking content for equality
}