a bug fix and minor improvements.
improvements on set_args methods in extension module.
improvements on nreg, timestep in sakura, and extension module interface.
refactoring of high order methods in sia.py.
minor improvements.
make the sign of 'alpha' the same as the two-body energy in universal_kepler_solver.
improvements in nreg.py
more improvements in nreg.py
more improvements in nreg.py (II)
now IC for binaries starts at apocentre. also some improvements in nreg.py and sia.py.
some improvements in particles modules and sia.py; also adds minor optimizations in kepler solver.
attempt to fix a bug in extension module when running it on GPUs.
This is because of bug 4775 on old versions of glibc.