Create util/sync.pl

- Slay the Hydra!

Signed-off-by: Xiong Changnian <xiong@cpan.org>
It's ever so much worse than you thought.

Signed-off-by: Xiong Changnian <xiong@cpan.org>
Implement Unison-based config folder sync scheme.

Signed-off-by: Xiong Changnian <xiong@cpan.org>
Merge branch 'util-sync' into devel

Signed-off-by: Xiong Changnian <xiong@cpan.org>