Added the possibility to have different boundary conditions per species.

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.

runs/1D_Cathode/inputCart.json

@@ -21,8 +21,12 @@
     {"name": "Electron", "type": "charged", "mass": 9.109e-31, "charge":-1.0, "weight": 1.0e1}
   ],
   "boundary": [ 
-    {"name": "Cathode",  "type": "absorption", "physicalSurface": 1},
-    {"name": "Infinite", "type": "absorption", "physicalSurface": 2}
+    {"name": "Cathode",  "physicalSurface": 1, "bTypes": [
+                                                 {"type": "absorption"}
+                                               ]},
+    {"name": "Infinite", "physicalSurface": 2, "bTypes": [
+                                                 {"type": "absorption"}
+                                               ]}
   ],
   "boundaryEM": [
     {"name": "Cathode",  "type": "dirichlet", "potential":  -10.0, "physicalSurface": 1},

runs/1D_Cathode/inputRad.json

@@ -21,8 +21,12 @@
     {"name": "Electron", "type": "charged", "mass": 9.109e-31, "charge":-1.0, "weight": 1.0e1}
   ],
   "boundary": [ 
-    {"name": "Cathode",  "type": "absorption", "physicalSurface": 1},
-    {"name": "Infinite", "type": "absorption", "physicalSurface": 2}
+    {"name": "Cathode",  "physicalSurface": 1, "bTypes": [
+                                                 {"type": "absorption"}
+                                                ]},
+    {"name": "Infinite", "physicalSurface": 2, "bTypes": [
+                                                  {"type": "absorption"}
+                                                ]}
   ],
   "boundaryEM": [
     {"name": "Cathode",  "type": "dirichlet", "potential":  -10.0, "physicalSurface": 1},