remove prototype pathops code

experimental/Intersection/QuadraticUtilities.h

-/*
- * Copyright 2012 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#if !defined QUADRATIC_UTILITIES_H
-#define QUADRATIC_UTILITIES_H
-
-#include "DataTypes.h"
-
-int add_valid_ts(double s[], int realRoots, double* t);
-void chop_at(const Quadratic& src, QuadraticPair& dst, double t);
-double dx_at_t(const Quadratic& , double t);
-double dy_at_t(const Quadratic& , double t);
-//void dxdy_at_t(const Quadratic& , double t, _Point& xy);
-_Vector dxdy_at_t(const Quadratic& , double t);
-
-double nearestT(const Quadratic& , const _Point& );
-bool point_in_hull(const Quadratic& , const _Point& );
-
-/* Parameterization form, given A*t*t + 2*B*t*(1-t) + C*(1-t)*(1-t)
- *
- * a = A - 2*B +   C
- * b =     2*B - 2*C
- * c =             C
- */
-inline void set_abc(const double* quad, double& a, double& b, double& c) {
-    a = quad[0];     // a = A
-    b = 2 * quad[2]; // b =     2*B
-    c = quad[4];     // c =             C
-    b -= c;          // b =     2*B -   C
-    a -= b;          // a = A - 2*B +   C
-    b -= c;          // b =     2*B - 2*C
-}
-
-int quadraticRootsReal(double A, double B, double C, double t[2]);
-int quadraticRootsValidT(const double A, const double B, const double C, double s[2]);
-void sub_divide(const Quadratic& src, double t1, double t2, Quadratic& dst);
-_Point sub_divide(const Quadratic& src, const _Point& a, const _Point& c, double t1, double t2);
-void toCubic(const Quadratic& , Cubic& );
-_Point top(const Quadratic& , double startT, double endT);
-void xy_at_t(const Quadratic& , double t, double& x, double& y);
-_Point xy_at_t(const Quadratic& , double t);
-
-#endif