neBEM

• Trim down Element struct (removing variables that are unused, redundant, or can be computed on the fly).
• Add new function ElePFAtPoint1 to be called instead of ElePFAtPoint if PrimAfter is set to <= 0 i. e. if the potential and field are always computed based on the elements and not on the primitives. In the new function, the outer loop is over the elements and the inner loops over the periodic copies. For the GEM example, the new function gives a ~30% speed up.
• Removed the parts of the code related to mirror periodicity from ComputeProperties.c, as they are never called.
• Reduced the number of global variables.
• Collect all code related to saving geometry information for Gnuplot in a dedicated function.