some errors in bound_min.cpp

[realwill]

error lines may be added to get wrong rectangle, so inf is got.
for (int kk = 0; kk < k; kk ++)
{
if (abs(atan2(Lc[kk].y / Lc[kk].z, Lc[kk].x / Lc[kk].z) - atan2(ln.y / ln.z, ln.x / ln.z)) < 0.3)
{
replace = 0;
break;
}
}
the code can be added in CBoundMin::calculate() to control add the lines.