More realistic parameters
Paralellization of the code and bugs fixed.

As the potential calculation is a really intensive process,
now it can be done in several cores. Right now the code
automatically creates two processes for this purpose, but I
intend to make the number of processes an optional parameter
in a future commit.

Also, some bugs and improvements were made in the temperature
calculation for the gas.
Simple temperature analysis script added.

It simply prints the cylyndrical coordinate \rho
and the temperature for each gas particle.
Small header change.