Added a script and log file for calculating the numerical Jacobian for an exponential curve.
This uses the data at http://thread.gmane.org/gmane.science.nmr.relax.devel/6807/focus=6840 and
calculates the Jacobian using the numdifftools.Jacobian object construct and obtain the matrix, both
at the minimum and at a point away from the minimum. The values will be used to construct a unit
test to check the C module implementation.
