add ACEScg as working profile and sole some bugs in selection primaries

rtengine/iccmatrices.h

@@ -66,6 +66,18 @@ constexpr double xyz_sRGB[3][3] = {
     {0.0139322,  0.0971045,  0.7141733}
 };
 
+constexpr double xyz_ACEScg[3][3] = {
+    {0.68988,  0.14977, 0.12456},
+    {0.28452,  0.67169,  0.04379},
+    {-0.00604,  0.01001,  0.82094}
+};
+
+constexpr double ACEScg_xyz[3][3] = {
+    {1.59266,  -0.351803, -0.22288},
+    {-0.67593,  1.639273, 0.015117},
+    {0.019959,  -0.022576, 1.21629}
+};
+
 constexpr double sRGB_xyz[3][3] = {
     {3.1338561, -1.6168667, -0.4906146},
     { -0.9787684,  1.9161415,  0.0334540},