fixed SafeFixedDiv(fixed num, fixed den)
Performs safe division: if denumerator is 0, the result is 0 and no error happens.
Fixed-point version, for integers see SafeDiv.
SafeFixedDiv(6.0, 3.0) -> 2.0 SafeFixedDiv(6.0, 0.0) -> 0 SafeFixedDiv(6.0, 5.0) -> 1.2