Function lchabToMhvc

Converts LCHab to Munsell HVC by inverting mhvcToLchab() with a simple iteration algorithm, which is almost the same as the one in "An Open-Source Inversion Algorithm for the Munsell Renotation" by Paul Centore, 2011:

• V := lToMunsellValue(L*);
• C₀ := C*_ab / 5.5;
• H₀ := h_ab * 100/360;
• C_n+1 := C_n + factor * ΔC_n;
• H_n+1 := H_n + factor * ΔH_n.

ΔH_n and ΔC_n are internally calculated at every step. This function returns Munsell HVC values if C₀ ≦ threshold or if V ≦ threshold or when max(ΔH_n, ΔC_n) falls below threshold.

Note that the given values are assumed to be under Illuminant C. I don't recommend you use this function if you are not sure what that means.