from v1.05 of interferometry:
============================

In primary_beams.py,

(*) Added a new function to compute airy disk patterns of uniformly illuminated
circular disks. The funciton is named airy_disk_pattern()
(*) Modified primary_beam_generator() to accept 'hera' for telescope input and
compute the primary beam using the newly added airy_disk_pattern()
(*) Replaced the use of variable phase_center in all routines with
pointing_center.

In baseline_delay_horizon.py,

(*) Changed docstring of delay_envelope() to indicate that maximum delay is
given by [:,:,0]-[:,:,1]

In interferometery.py,

(*) In baseline_generator(), added an input keyword ant_id to keep track of
antennas in the baseline vectors. The output now also contains ids of the
antenna pair. Docstring changed accordingly
(*) In baseline_generator(), when antenna locations are specified as a numpy
array, baselines were calculated as i-j for j > i. THis is inconsisntent with
baselines if the input was a list of lists where baseliens were calculated as
j-i for j > i. Now they are all made consistent with j-i for j>i.
(*) Added Tsys initialization from init_file in __init__() member function of
class InterferometerArray
(*) Added a new attribute lag_psf that denotes the inverse fourier transform of
bandpass shape to class InterferometerArray. It is initialized in __init__()
member function and computed in member function delay_transform(). It is saved
using save() member function
(*) Added description of attribute bp_wts to docstring of class
InterferometerArray which was not done earlier
(*) Modified delay_transform() member function of class InterferometerArray to
have output in units of Jy Hz instead of Jy as before. This was done by
multiplying the IFFT by number of frequency channels (including padded channels,
if any) and the frequency resolution. This automatically makes the amplitude
invariant to padding and hence no need to correct for amplitudes due to padding
factor at the downsampling step. Hence, the amplitude correction introduced in
the previous version is now removed.
(*) Replaced use of phase_center in calling primary_beam routines with
pointing_center to reflect the same changes made in the primary_beam routines.