Files and types with 'Cyl' have been changed to '2DCyl' to better
differentiate between the two types of 2D geometry.
Solvers for charged and neutral particles in 2D Cartesian space.
Added solveds for 1D neutral particles (this branch is not the place to
do it, but it was a minor change).
User Manual updated with the new accepted options.
A boundary condition for each species must be indicated in the case
file.
This opens the door to use boundary conditions with different parameters
(for example, a wall temperature, coefficients for reflection or
absorption...)
The examples included with the code have been updated accordently.
