Blender Git Loki

Adding a new SPH solver that is more physically accurate. See patch #29681

http://projects.blender.org/tracker/index.php?func=detail&aid=29681&group_id=9&atid=127

The solver was mostly implemented by John Mansour at VPAC, with help from me and with funding from the AutoCRC. The SPH formulation is due to Gingold and Monaghan, and the smoothing kernel is due to Wendland.

This solver does not replace the old one; it is available as an option. Note that the new solver uses different units than the old one. The patch page has a couple of attachments that can be used to test the new solver, particularly sphclassical_dam_s0.01_grav.blend (ignore the earlier tests). The simulation in that file compares well with a physical experimental dam break; details in a paper by Changhong Hu and Makoto Sueyoshi, also referred to on that page.