FFTADD: enhancement
FFTADD: enhancement

- Use hadamard_mul to multiply beta_m_powers
- Taylor expansion performs directly at input vector. At the end of
  this step, input vector will be list of polynomials h_i(x). Hence,
  g0 and g1 are calculated as even and odd indexed sub-array of input.

vrancurel/ntl,vrancurel/ntl,vrancurel/ntl