add dens to interpPotential and fix fabs(z)
better handling of symmetric z, improved documentation
add dvcircdR
switch to potentialArgs and better freeing of allocated memory
add header file with definition of parser in preparation for interpolated forces
make parser not inline
add break
new parsing of potential for action calculation
parse interpolated potential for orbit integration
add force evaluations to header file
interpolate R and z forces and start on evaluating these
calculate R and z forces on a grid for interpolation in C
 add interpolated potential to C
 add interpolated potential to C
add necessary files for compiling the interpolation library
fix interpolated potential's zforce in C
speed up E evaluation
array evaluation of zforce fix
add C evaluation of interpolated forces
add potforactions=True in eval_potential