include collisionnal fragmentation in mercury

[GoogleCodeExporter]

an option currently exist for:
 include collisional fragmentation = no
but nothing is implemented. 

Try some of the new papers to include this in mercury

Title: Collisions between Gravity-Dominated Bodies: 2. The Diversity of Impact
Authors: S. T. Stewart and Z. M. Leinhardt
\\ ( http://arxiv.org/abs/1109.4588 ,  3437kb)

Or

Genda, Kokubo, 2011 : Merging Criteria for Giant Impacts of Protoplanets
\source{http://arxiv.org/abs/1109.4330}

Original issue reported on code.google.com by [email protected] on 22 Sep 2011 at 2:05