Ionization boundary condition fully tested.

Documentation updated properly.

3D Cartesian geometry also tested.
Documentation updated properly.

Added weighting probability in the injection of particles.

src/modules/mesh/moduleMeshBoundary.f90

@@ -137,14 +137,15 @@ MODULE moduleMeshBoundary
 
           !Create the new pair of particles
           DO p = 1, ionizationPair
-            ALLOCATE(newElectron)
-            ALLOCATE(newIon)
-
             !Assign random velocity to the neutral
             v0(1) = bound%v0(1) + bound%vTh*randomMaxwellian()
             v0(2) = bound%v0(2) + bound%vTh*randomMaxwellian()
             v0(3) = bound%v0(3) + bound%vTh*randomMaxwellian()
 
+            !Allocates the new particles
+            ALLOCATE(newElectron)
+            ALLOCATE(newIon)
+
             newElectron%sp = part%sp
             newIon%sp      = bound%sp