[evlatests] attenuator level tests cont.

[Walter Brisken]

Antenna 16 is working now after restarting the d30x modules.

L-band is working now in antenna 16.  Parameters for this receiver are now 
in the database.  It is possible the receiver isn't completely cooled yet 
so these values should be revisited again sometime.

It seems that the attenuator values for IFs B and C are swapped when being 
read from the database, both the RF and Output attenuator values.  This is 
observed for all bands.  IFs A and D do the right thing.  Sampler RMS 
values are in the expected range.

I'll test antenna 15 later tonight.

-W