[evlatests] Level setting software

[Barry Clark]

Using the existing level-set command, I have compared the table driven
setups we are now using with the results of the level set commands 
at X and C bands.  The results are uncontroversial - the two methods 
agree very well.  (With the possible exception of ea14-a, which might
could use toning down by a couple of DB.)

Sometime soon I'll do this for the possibly more controversial bands.

Table below lists input attenuator, output attenuator, the input power
measurement from the detector, the output power measurement, The rms
seen at the deformatter, the ALC level at the T5 (about -4 is considered
desirable), and the T5 synchronous detector (believed to be a reasonable
surogate for sensitivity).

X Band, with Walter's settings from the table.
      Inat Outat inpw   outpw  RMS T5ALC T5SD
ea14-a   0    10 -23.5  -32.1  8.9 -4.3  2.80 
ea14-c   0    13 -20.5  -30.8  8.8 -4.0  2.11
ea16-a   0     9 -24.9  -32.5  5.8 -1.5  1.84 
ea16-c   0    15 -22.0  -34.2  5.0 -2.6  2.10 
ea24-a   0    10 -22.7  -28.7 10.4 -3.9  1.7 (erratic) 
ea24-c   0    10 -22.8  -33.1  5.8 -4.1  1.10 
With Level setting software   
ea14-a   0     7 -23.5  -29.2 11.6 -4.6  2.48
ea14-c   0    13 -20.4  -30.5  8.6 -4.0  2.22
ea16-a   0     7 -25.0  -30.8  7.2 -2.4  1.90
ea16-c   0    11 -22.0  -30.4  8.3 -3.7  2.08
ea24-a   0    10 -22.8  -28.8 10.5 -4.1  1.7 (erratic) 
ea24-c   0    10 -23.0  -33.4  5.7 -4.1  2.12  
 
C Band, with Walter's settings from the table.
ea14-a   8    15 -22.5  -30.6  9.3 -4.1  2.76
ea14-c   4    15 -17.9  -26.8 12.7 -4.3  2.69
ea16-a   4    15 -18.2  -31.7  6.4 -2.4  4.00
ea16-c   7    15 -19.6  -31.2  7.5 -3.4  4.21
With Level setting software
ea14-a   7    15 -20.7  -29.8 10.0 -4.2  2.77
ea14-c   6    17 -20.9  -30.8  7.8 -3.6  2.72
ea16-a   6    12 -20.7  -30.9  7.3 -2.6  4.03
ea16-c   7    14 -19.6  -30.4  8.0 -3.6  4.24


It seems to me that we need an option for stong sources, for waiting
until on-source to do the final setup.  Unclear to me whether this 
should be done on the java side or the python script side.