Introduced scale factor for velocities

In ljmd.c, velocity units are such that v*dt has units angstroms,
so v has units 10**(5) m/s
In ASE, ase.units.kB is by default in eV/K.
Furthermore, ase.md.velocitydistribution calculates with masses in amu.
If you set force_temp=True, you end up with kB=1 and  amu=1,
so the units of V are sqrt(amu/kB) = 91.1837 m/s
So you have to divide ASE's velocities by 1096.687
or, since T\propto v**2, scale T by 8.31446714569e-7