Add parameter for binary saving.
WTIMESTEP / CMake changes:
- Optimize CMake instructions
- Intruduce option to print information on integration steps
Separate printpdata:
- Particle data printout moved to separate function
- Change exchange of paths from char to File*
Speed optimization for calc_accel:
- Faster calculation of acceleration by replacing the pow( ... ,1.5) function
Merge branch 'GSOC-Integrator'