path ops work in progress

src/pathops/SkQuarticRoot.cpp

 // from http://tog.acm.org/resources/GraphicsGems/gems/Roots3And4.c
 /*
  *  Roots3And4.c
  *
  *  Utility functions to find cubic and quartic roots,
  *  coefficients are passed like this:
  *
  *      c[0] + c[1]*x + c[2]*x^2 + c[3]*x^3 + c[4]*x^4 = 0
  *
  *  The functions return the number of non-complex roots and
@@ skipping 134 matching lines @@
         }
     }
     /* resubstitute */
     const double sub = a / 4;
     for (int i = 0; i < num; ++i) {
         s[i] -= sub;
     }
     // eliminate duplicates
     for (int i = 0; i < num - 1; ++i) {
         for (int j = i + 1; j < num; ) {
-            if (AlmostEqualUlps(s[i], s[j])) {
+            if (AlmostDequalUlps(s[i], s[j])) {
                 if (j < --num) {
                     s[j] = s[num];
                 }
             } else {
                 ++j;
             }
         }
     }
     return num;
 }