Added Pause feature
Ignored .depend because the timestamp is annoying
Added Electrostatic forces calculation
Switched to using std::abs() for collision detection so doubles would work
Got rid of the .depend file because it was annoying after all.
Added coloring to charged particles.
Particles are currently assigned random charges (nominally -1, 0, or 1) when placed.
Added Render Panning.
Moved render->physics coordinate logic into the render class.
Merge branch 'development'