First implementation of probing method

The code nows offer the possibility to obtain the distribution function
for a specific species in a 3D velocity grid at a determined position.

This is a simple method that just scatter the particles in one cell into
the velocity grid.

src/fpakc.f90

@@ -1,12 +1,13 @@
 !  FPAKC main program
 PROGRAM fpakc
+  USE moduleCompTime
+  USE moduleCaseParam
   USE moduleInput
-  USE moduleErrors
   USE moduleInject
   USE moduleSolver
   USE moduleMesh
-  USE moduleCompTime
-  USE moduleCaseParam
+  USE moduleProbe
+  USE moduleErrors
   USE OMP_LIB
   IMPLICIT NONE
 
@@ -84,6 +85,9 @@ PROGRAM fpakc
     !$OMP SINGLE
     tCoul = omp_get_wTime() - tCoul
 
+    !Do probing
+    CALL doProbes(t)
+
     !Reset particles
     tReset = omp_get_wtime()
     !$OMP END SINGLE