* Added various views and helper functions used by the mining
computation but which may be re-used in other parts.
* Added mining computation update type and associated update function
* New constants: game.resources.weightBase (the value used to compute
weights from mining settings) and game.resources.extraction (the
quantity extracted in a day from a full provider at difficulty 0)
Implemented resource regeneration computation in the
verse.compute_provider_regeneration() function.
Created the PLANET_RES_REGEN update type, and added the corresponding
implementation.
Added resource regeneration constants registration.
