Add 1.13 support with all clock supported!

Compatible with 1.12.2 and older version but the Comparator and Observer clock are not detected.

If you want to add support for older version you need to backport this patch to your minecraft version.
I have backport it for 1.12.2 if you need it (you need to compile spigot yourself):
BlockObserver.patch
BlockRedstoneComparator.patch

Other features:
- Improve code
- Add metrics with bstats