Add some frequency and amplitude modulation to the plot

One addition to the output struct, now contains an array of antenna names
Note that I forced GIT to add src/Makefile

Included effects of arrival time delay in the formulae for the waveforms (assuming a round earth)

Expressed output X sin(phi) + Y cos(phi) in the alternative form r sin(phi+offset)

Currently offset is printed in degrees.  Printing code assumes UTF-8 on the terminal. This may be fragile, I'm not sure.

I am calculating the second derivative of the mass quadrupole in the 2-dimensional plane
orthogonal to the line of site.  The mass quadrupole is traceless w.r.t. to the two-dimensional
metric in that plane