fixed all warnings

[exit-failure]

Added checks to fix all warnings when the radius of cylinder would be zero. Also fixed warnings where the radius parameters of cylinders were ambiguous.

[CameronBrooks11]

Similar here, I was getting:
WARNING: Cylinder parameters ambiguous in file ../hingebox_code.scad, line 566
WARNING: Cylinder parameters ambiguous in file ../hingebox_code.scad, line 567
WARNING: Cylinder parameters ambiguous in file ../hingebox_code.scad, line 568
WARNING: Cylinder parameters ambiguous in file ../hingebox_code.scad, line 569

So I fixed lines 562-571 in hingedbox_code.scad:
module base_box(d, top_inset=false, f=corner_fn) {
b = corner_radius;
tb = top_inset ? top_inset : b;
hull() {
translate([b, b, 0]) cylinder(h=d.z, r1=b, r2=tb, $fn=f);
translate([b, d.y-b, 0]) cylinder(h=d.z, r1=b, r2=tb, $fn=f);
translate([d.x-b, b, 0]) cylinder(h=d.z, r1=b, r2=tb, $fn=f);
translate([d.x-b, d.y-b, 0]) cylinder(h=d.z, r1=b, r2=tb, $fn=f);
}
}