computeOffsetOrigin may not have solutions

[gistrec]

Function computeOffsetOrigin may not have solutions, e.g.:

// 'over' the pole.
SphericalUtil::computeOffsetOrigin(LatLng(80, 0), M_PI * MathUtil::EARTH_RADIUS / 4, 180);

// A distance that doesn't fit on the earth.
SphericalUtil::computeOffsetOrigin(LatLng(80, 0), M_PI  * MathUtil::EARTH_RADIUS / 4, 90);

the function should return the status