Cleanup: Replace ABS/SQUARE/CUBE with function calls

While it might be handy to have type-less functionality which is
similar to how C++ math is implemented it can not be easily achieved
with just preprocessor in a way which does not have side-effects on
wrong usage.

There macros where often used on a non-trivial expression, and there
was at least one usage where it was causing an actual side effect/bug
on Windows (see change around square_f(sh[index++]) in studiolight.c).

For such cases it is handy to have a function which is guaranteed to
have zero side-effects. The motivation behind actually removing the
macros is that there is already a way to do similar calculation. Also,
not having such macros is a way to guarantee that its usage is not
changed in a way which have side-effects and that it's not used as an
inspiration for cases where it should not be used.

Differential Revision: https://developer.blender.org/D7051

source/blender/editors/interface/interface_utils.c

@@ -525,7 +525,7 @@ int UI_calc_float_precision(int prec, double value)
    * this is so 0.00001 is not displayed as 0.00,
    * _but_, this is only for small values si 10.0001 will not get the same treatment.
    */
-  value = ABS(value);
+  value = fabs(value);
   if ((value < pow10_neg[prec]) && (value > (1.0 / max_pow))) {
     int value_i = (int)((value * max_pow) + 0.5);
     if (value_i != 0) {