First commit of code.

New functionality:
- DSMC module:
  - 2D cyl geometry
    - GMSH file format
    - Elastic cross-section for Argon-Argon collisions.
    - Basic boundary conditions: reflection, absorption and axis
      symmetry.

Bugs fixed:

Other comments:
- Still searching for name.

src/modules/moduleErrors.f95

@@ -0,0 +1,43 @@
+!moduleErrors: Manages the different type of errors the program can produce.
+!              By errors we understand critical errors (that stop the program),
+!              warnings (that only output a message with a WARNING tag),
+!              o verbose outputs that can be used for debugging porpouse.
+MODULE moduleErrors
+  CONTAINS
+    SUBROUTINE criticalError(msg, pgr)
+      IMPLICIT NONE
+
+      CHARACTER(*), INTENT(in):: msg, pgr
+      CHARACTER(:), ALLOCATABLE:: errorMsg
+
+      errorMsg = "CRITICAL error in " // pgr // " with message:" // NEW_LINE('A') //  msg
+
+      ERROR STOP errorMsg
+
+    END SUBROUTINE criticalError
+
+    SUBROUTINE warningError(msg)
+      IMPLICIT NONE
+
+      CHARACTER(*), INTENT(in):: msg
+      CHARACTER(:), ALLOCATABLE:: errorMsg
+
+      errorMsg  = "WARNING: " // msg
+
+      WRITE (*, '(A)') errorMsg
+
+    END SUBROUTINE warningError
+
+    SUBROUTINE verboseError(msg)
+      IMPLICIT NONE
+
+      CHARACTER(*), INTENT(in):: msg
+      CHARACTER(:), ALLOCATABLE:: errorMsg
+
+      errorMsg  = msg
+
+      WRITE (*, '(A)') errorMsg
+
+    END SUBROUTINE verboseError
+
+END MODULE moduleErrors