====== Generic filtering of possible activities over plots ======

From the very beginning, RegMAS implement a dynamic decision matrix, where activities and resources depend on the specific conditions of the agent (e.g. available plots).
This task would modify the functions related to the matrix initialization and upgrading with a //generic// framework for checking if activities or resources should be added or not to the matrix.
The present implementation is too much tailored to the needs of the farmers agents.