MS_MAKE_TRACE - Create a pair of orthogonal traces

[time, T00, T90] = MS_make_trace(spol, dfreq, max_tlag)

Inputs:
   dfreq (scalar)    : Dominant frequency of trace (Hz)
   spol (scalar)     : source polarisation direction (degrees)
   max_tlag (scalar) : maximum lag time to be accommodated on trace (s)

Outputs:
   time (vector) : Series of time points where amplitudes are known (s)
   T00 (vector)  : Series of amplitudes of transverse wave #1.
   T90 (vector)  : Series of amplitudes of transverse wave #2.

MS_make_trace creates a time series of the amplitude of displacement in
two orthogonal directions (e.g. of waves or wavelets) stored in time,
T00 and T90. In the current version only a (first-derivative) Gaussian
wavelet can be generated. Future additional optional arguments will
allow other choices.