lua support

ron serialization has been traded out for lua

This makes it easier to preset systems and actually makes things easier to read. Even without knowing how to code, some syntax is practically markup.

for i = 1, 10 do
   for j = 1, 10 do
      add_body({x = 20 * i, y = 20 * j, mass = 0.1, rad = 2})
   end
end

This lua file replaces a >1k line ron file.

For a simple preset which doesn't need any logic:

add_bodies(
	{x = 125.000, y = 70.000, x_vel = 0.000, y_vel = 1.000, mass = 80.000, rad = 4.500},
	{x = 175.000, y = 70.000, x_vel = 0.000, y_vel = -1.000, mass = 80.000, rad = 4.500},
	{x = -30.000, y = 70.000, x_vel = 0.000, y_vel = -1.000, mass = 0.500, rad = 1.000},
	{x = 330.000, y = 70.000, x_vel = 0.000, y_vel = 1.000, mass = 0.500, rad = 1.000}
)

This is practically just markup and more legible than the ron was

There's probably some bugs