1.52

	- [Ooops!!!] The option -correct was somewhat misfunctioning. In fact,
	it was overcorrecting for the filtering effects... Sorry! 
	This may affect prior calibrations if the calibrators and science
	sources were reduced with very different options (e.g. default and
	via '-deep'). The point of '-correct' is exactly to eliminate this
	dependence on reduction options. My apologies if this caused you a
	problem. At least, it should be all good now :-).

	- Made various modifications on bright.cfg (invoked via the -bright 
	flag). This should improve the reduction of very bright (>>1000 Jy)
	sources, such as bright planets...

	- Debugged and improved the power spectrum utilities. It seems that 
	power spectra were not entirely well-normalized in prior releases. 
	This does not affect those who have not been using the -spectrum=
	or -skySpectrum features before.

	- Added BeamEfficiencyModel. This model aims to estimate the 
	main-beam efficiency variations (relative to the flat-field gains 
	based on the correlated atmospheric response) in the field of view. 
	This helps convergence on bright (>1000 Jy) sources and produces better
	images for these. For faint sources (<10Jy) its effect is negligible. 
	Therefore, the model is disabled in the '-faint' reduction mode. It is
	also disabled in the default reduction for the time being, since it is
	an experimental feature, and sufficient testing is required. If you
	wish to use it, enable via the '-Ibeam=auto' option or 
	BEAM_EFFICIENCY_TURN = auto configuration key. Then, the model 
	auto-activates based on the observed brightness of the source 
	(activates whenever the average peak signal-to-noise per scan 
	exceeds the greater or 30 or 10% of the peak). 
	The auto-activation is default in the '-bright' reduction mode.
	(Note.) The main-beam efficiency seems to vary around the 10-30% level 
	accross the field of view.

	- help screen for RowBiasDrift model was incorrect. Fixed.	

