Game of Life - GIS
Conway's model
This Version: Ported to GIS representation, December 2018
- naive port (each cell is an active entity)

The model consists on a lattice where cells can be "alive" or "dead". Each cell depends on its eight neighbours and at each time step determine their state according to the following rules:
- Any live cell with fewer than two live neighbours dies, as if caused by underpopulation.
- Any live cell with two or three live neighbours lives on to the next generation.
- Any live cell with more than three live neighbours dies, as if by overpopulation.
- Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.

Depending on the initial conditions the configuration can reach a stable state or enter one among severl cyclical patterns.

The model is configurated so that the user can impose a random number of living
cells (par. PercActive), defined as the share of existing cells being alive. If
this parameter is negative the model asks for a file containing the initially
living cells. These are contained into text files storing at each line a couple
of positive integers, indicating the row and column of the active cell.

The model is endowed with a "brake" slowing down the speed of execution, useful
to appreciate the dynamics. Parameter TimeSleep expresses the milliseconds to
wait before moving to compute the next step.

New options in GIS ported version:

- added option to choose wrapping:
  there are 2^4 options. We use a bit-code (0=off):
  0-bit: left     : 0=0 1=1
  1-bit: right    : 0=0 1=2
  2-bit: top      : 0=0 1=4
  3-bit: bottom   : 0=0 1=8
  sum the values to generate desired wrapping (e.g. 15 - torus world, default)

- added option to choose continuous vs parallel (default) update.
