Carr-Madan and Hilbert method

[GaetanoCodes]

Hi Justin,

2 files are modified:

1. BilateralGamma.py : I just added a multiplication by T for the 2nd cumulants (I had this diffuclty during my internship, previously, just sigma2 was added. One should add sigma2*T) cumulants.c2 += T * self.sigma**2
2. Test_suite.py: I added the two new fourier methods.

5 files are added:

1. One introducing the Tempered Stable model (based on your models)
2. 2 related to Carr Madan (Test and Pricer)
3. 2 related to Hilbert (Test and Pricer)

Feel free to reach me if anything is incorrect!