Previously some nodes like "mcl_flowers:double_grass_top" would be
undiggable. This was because they did not define _mcl_hardness and it
was not defaulted to 0 in all parts of _mcl_autogroup.
Requiring tool definitions to call a function in _mcl_autogroup means
that they need to be loaded after _mcl_autogroup. This can cause
problems because _mcl_autogroup needs to be loaded after all tool and
node definitions are completed.
Because of this the API is changed so tool definitions instead put the
data used to generate groupcaps in the custom field
_mcl_autogroup_groupcaps. _mcl_autogroup will then go through all
registered tools and update the groupcaps for every tool where this
field is present. This means that no mod ever has to depend on
_mcl_autogroup.
These changes are primarly made to make mcl_autogroup more efficient.
Previously enchanted tools required storing around 21 kB of metadata due
to the way the previous version of the mod was implemented. This caused
a lot of lag and a huge amount of network traffic. With the changes
enchanted tools won't require more than 1 kB of metadata.
The mod is also rewritten to use an API to register digging groups and
compute the groupcaps for tools. This will make it easier for modders
to register custom digging groups.
The mod is now split up into two parts. One part called "mcl_autogroup"
to implement the API for registering custom digging groups, and the
other part called "_mcl_autogroup" which contains most of the code which
has to be loaded after most mods.