MilkyWay

Worked on nativePP. Can now compile it with a main method to test the C code. Still won't load though...

Changed threadedPP to use only the number of threads the same as the number of processors (as any extra are just extra overhead to synchronize and manage, calculation can't be done any faster than one thread per core). /* TODO perhaps use fork/join rather than splitting the work evenly to further improve performance... */

Added C files for native particle-particle calculation (to see if can optimize further memory and processor usage by using native code).

Made stepping leapfrog.