Most of modules organized

Most of the modules are organized in subfolders.

Maybe some big re-organization is needed in the future, but for now I am
happy.

src/modules/common/moduleConstParam.f90

@@ -0,0 +1,17 @@
+!Physical and mathematical constants
+MODULE moduleConstParam
+  IMPLICIT NONE
+
+  PUBLIC
+
+  REAL(8), PARAMETER:: PI  = 4.D0*DATAN(1.D0) !number pi
+  REAL(8), PARAMETER:: PI2 = 2.D0*PI !2*pi
+  REAL(8), PARAMETER:: PI8 = 8.D0*PI !2*pi
+  REAL(8), PARAMETER:: sccm2atomPerS = 4.5D17 !sccm to atom s^-1
+  REAL(8), PARAMETER:: qe = 1.60217662D-19 !Elementary charge
+  REAL(8), PARAMETER:: kb = 1.38064852D-23 !Boltzmann constants SI
+  REAL(8), PARAMETER:: eV2J = qe !Electron volt to Joule conversion
+  REAL(8), PARAMETER:: eps_0 = 8.8542D-12 !Epsilon_0
+
+END MODULE moduleConstParam
+