BUG: lhetero = .true. uses incorrect values for thls and rssoilmin

[rbschulte]

With lhetero = .true. in NAMSURFACE, two surface variables are incorrectly initialized in modsurface.f90: thls and rssoilmin.
This leads to significantly different outcomes for two runs which only differ in the lhetero swich (.true./.false.) for isurf = 1.

modsurface.f90, line 442:
thls = 300
This overwrites the thls specified in namoptions PHYSICS.

modsurface.f90, line 1580:
rssoilmin (i,j) = rsmin_patch (tempx,tempy)
Here, rssoilmin is set equal to rsmin.

With the help of Bart, we solved the issues by removing line 442 and by adding a new input field for rssoilmin in the input file surface.interactive.inp.xxx. With these two corrections, the aforementioned two runs produce near identical results.
Below, I added my corrected versions of modsurface.f90 and modsurfdata.f90 as .txt files
modsurface.f90.txt
modsurfdata.f90.txt