Now, if no normal is provided to an injection in the input file, the
velocity direction of the particles is chosen to be the surface normal.
This allows to inject particles from curves, corners... without having
to provide a direction or declaring multiple injections.
Output for the example ALPHIE_Grid.
Found an issue when multiple injections were used with species with
different time steps.
Modification to the way to compute the ionization boundary:
The maximum number of ionizations is computed by eRel/eThreshold
(relative energy / threshold of ionization)
For each possible ionization, the probability of ionization is
computed based on the density of neutrals, cross section and effective
time divided by the number of maximum ionizations.
If an ionization takes place, the ionization energy is substracted
from the relative energy.
Documentation updated properly.
3D Cartesian geometry also tested.
Documentation updated properly.
Added weighting probability in the injection of particles.
Possibility to input initial species distributions (density, velocity
and temperature) via an input file for each species.
New moduleRandom includes function to generate random numbers in
different ways (still uses) the implicit RANDOM_NUMBER().
Now collisions can have a different time step.
Added species name to output names as it was starting to get confusing
in Gmsh for multiple species.
Output filenames adapted to match any number of iterations.
Maxwellian and Diract Delta distributions have been implemented.
The input for injection of particles should be rewritten to allow more
clear input file.
