DONE
X change mygnuplot to do robust fitting
X accelerate npairs.pl
X do the scripts to generate gnuplot graphs automatically
X do the graphs for 
  X samples
  X schuster-vs-pcp
  X pcp all three
X package things in all.tar

TODO:
- pass all through perl5 -w and 'strict'
- put lsfit.pl etc into a package 'regression.pm'

