[evlatests] antenna 21 pointing and other parameters

[Ken Sowinski]

I have updated the pointing and X band collimation
parameters based on the pointing run from April 14.
In addition the large elevation collimation of
27 arc-min was supplied as a first guess for L and
K bands.  Thus K band stands a little better chance
of working now.  K band focus was also changed to 6 cm
on the grounds that it ought to be close to the
X band focus setting.