[Halld-offline] Data Challenge particle.dat

[Paul Mattione]

Hey guys, I've just updated the particle.dat file for data challenge 2; it turns out we were using an older version of this file.  So if you do an svn checkout of:
svn checkout https://halldsvn.jlab.org/repos/trunk/data_challenge/02/conditions
you'll get the new file.  However, the data challenge conditions webpage is still out of date; Mark, can you update it?  Thanks.  

 - Paul