[Ifeffit] Problems running athena/tkatoms

[Matt Newville]

Earlier today, Bruce wrote:

> Matt will (I presume) be including this fix in the next
> release of ifeffit.  Having solved that problem, we will be
> free to move on to the next problem!!!

I am posting ifeffit-1.0071.tar.gz today with this new perl
installation scheme, and attempts to address a few other issues
that have cropped up on unixes.  I'm not sure all these issues
have been resolved, but they're ready for broader testing.

For PGPLOT, there have been issues using pre-installed binary
versions, and use of the PNG driver to create PNG output files.
I updated PGPLOT_install so that it now installs both PNG and
GIF files, though either or both can be turned off with
  PGPLOT_install --no-png --no-gif

To use PNG, the png and zlib libraries must be installed (they
are on most linuxes, but may need installation on other Unix
variants).  Because of this dependency, I also changed several
parts of the Ifeffit configuration script so that it now checks
the PGPLOT installation to find out which drivers to use and
how to link with PGPLOT.

The upshot is that configure should now work with pre-installed
PGPLOT libraries (as from Debian or Fink), and PNG output is
supported.  A side-effect is that 'configure' now works on Mac
OS X, though there are still some issues with the full build on
that system.

I tested this on linux (2.4, RedHat 7.1) and Mac OS X.  There
were some problems installing the perl module on Mac OS X that
I have not tracked down.

The other significant changes are that
 - plotting in ifeffit can now do error bars:
      > plot data.x, data.y, dy=data.dy
   will plot error bars at each point:  data.y+/-data.dy

 - giving only one array to plot will use that as y, and
   the previous value of x:
      > newplot data.energy, data.xmu
      > plot data.bkg
   If it is a 'newplot':
       newplot data.bkg
   the x-axis will be the array index.

 - updated Reference Manual (though it's still not done!)

I expect to post a windows version based on 1.0071 later
this week.

As always, comments and suggestions are welcome.  In
particular, suggestions for additional functionality and
improvements to the existing applications would be greatly
appreciated.

Thanks,

--Matt