Reduces the visibility of all fields to private and create setters/getters
when necessary. Exceptions are fields with GuiSync as these need to be
public.
Reduces the visibility of internal methods to private/protected/default when possible.
Prioritized inventories are not longer used twice for storing leftover
items and thus finally reporting twice the amount of storable items when
they are the only possible option to store something.
Also fixes import buses now respecting the amount of storable items inside
the network instead of trying to place the exported items back and failing
on any restricted inventory, potentially voiding the overflow.
Fixes#1892
Deprecates the old usage of the AEItemDefinitions via the direct method access of
* blocks()
* parts()
* items()
* materials()
and thus use the new re-direct via definitions().
All definitions are now initialized, no matter what. But SubItems, Items and Blocks are not registered, if by chance are disabled.