[Pafgbt] GBT PAF Software Correlator

[Rick Fisher]

Instructions for processing 0.6 MHz bandwidth data from the GBT PAF with 
the software FX correlator are posted at

http://www.cv.nrao.edu/~rfisher/ArrayFeed/software_correlator.html

I'm continuing to clean up loose ends and look for bugs, but I think it's 
pretty close to being ready for the upcoming run on the GBT.  I've been 
using some test data that Anish wrote to the data acquisition disks for 
debugging, but a more complete test will come when the PAF goes to the 
outdoor test building.  At the moment the FITS iles are being written to 
my scratch directory, and we'll need to decide as a goup how the 
final directory paths should be set up and the appropriate write 
permissions created.

Rick