make gridcode filename blue

cleaned up some of the verbosity to be more like binary_grid and less annoying

Merge branch 'auto_resolution' of gitlab.eps.surrey.ac.uk:ri0005/binary_c-python into auto_resolution

implemented binary_grid-style statistics over last n_logging_stats verbose outputs (50 by default)

added ANSI colour to output if in a terminal (i.e. with a tty)

fixed the cmd-line parser to work in the form x=y as intended (downside: no help output, but that just said how to use the old parser which doesn't exist now)

updated the internal API for how grids are constructed to simplify the code

add option such that when resolution==0, the resolution is calculated automatically from the sample list.

add delete_grid_variable function

In my CEMP simulations, I use the above with something like this to zoom in around 0.8Msun in M1:

emp_population.update_grid_variable(
    name="lnm1",
    spacingfunc="gaussian_zoom(np.log(0.4),np.log(6.0),np.log(0.8),0.05,0.99,100)",
    resolution=0
)