Adapt the termal boundary conditions

The changes to the termal boundary conditions enabes the uses of 100
coefficient of spherical harmonics. Also the set of mode l=0 and m=0
automatically to 1 is commented out, since this affects the BC set.
Now the thermal BC s_top and s_bot need to be defined precisely.

Author: ygaillard

src/init_fields.f90

@@ -62,7 +62,7 @@ module init_fields
    real(cp), public :: amp_s1,amp_s2,amp_v1,amp_b1,amp_xi1,amp_xi2
 
    !----- Entropy at CMB and ICB (input):
-   integer, public, parameter :: n_s_bounds=20
+   integer, public, parameter :: n_s_bounds=100
    real(cp), public :: s_bot(4*n_s_bounds)  ! input variables for tops,bots
    real(cp), public :: s_top(4*n_s_bounds)
    complex(cp), public, allocatable :: tops(:,:)

src/preCalculations.f90

@@ -415,8 +415,8 @@ subroutine preCalc(tscheme)
 
          if ( ktops == 1 .and. kbots == 1 ) then ! Fixed entropy
 
-            tops(0,0)=0.0_cp
-            bots(0,0)=sq4pi
+            ! tops(0,0)=0.0_cp
+            ! bots(0,0)=sq4pi
 
          else if ( ktops == 3 .and. kbots == 3 ) then ! Fixed temperature contrast