Added new modes to set_info

1- The mode='remove' has been added, so the user can do:
- Fickian_alg.set_pore_info(label='Dirichlet', mode='remove')   , this
will remove the label completely.
-
Fickian_alg.set_pore_info(label="Dirichlet,locations=loc1,mode='remove')
, this will change the values in loc1 for Dirichlet label to False.
2- Now set_info accepts to extend the size of label='all', and also for
the other labels, it will add False for the new added locations.