Apply a mirror/reflection transformation to this matrix that reflects through the given plane
specified via the plane normal.
<p>
If <code>M</code> is <code>this</code> matrix and <code>R</code> the reflection matrix,
then the new matrix will be <code>M * R</code>. So when transforming a
vector <code>v</code> with the new matrix by using <code>M * R * v</code>, the
reflection will be applied first!
Apply a mirror/reflection transformation to this matrix that reflects through the given plane specified via the plane normal. <p> If <code>M</code> is <code>this</code> matrix and <code>R</code> the reflection matrix, then the new matrix will be <code>M * R</code>. So when transforming a vector <code>v</code> with the new matrix by using <code>M * R * v</code>, the reflection will be applied first!
@param normal the plane normal @return this