ERT-723: Added function ecl_grid_reset_actnum()
Merge pull request #563 from joakim-hove/ERT-723-reset-actnum

ERT-723: Added function ecl_grid_reset_actnum()
Merge pull request #564 from joakim-hove/ERT-723-reset-actnum

ERT-723: Added function ecl_grid_reset_actnum()
Merge pull request #565 from joakim-hove/ERT-723-reset-actnum

ERT-723: Removed unused arguments.