fixed mLayerHeight issue with celia test

build/source/dshare/popMetadat.f90

build/source/engine/coupled_em.f90

build/source/engine/opSplittin.f90

utils/laugh_tests/celia1990/verification_data/runinfo.txt

...ication_data/summa_celia1990_G1-1_timestep_notsundials.nc

utils/laugh_tests/colbeck1976/run_test_summa.sh

...sts/colbeck1976/settings/summa_zDecisions_colbeck1976.txt

...k1976/verification_data/colbeck1976-exp2_G1-1_timestep.nc

...k1976/verification_data/colbeck1976-exp3_G1-1_timestep.nc

utils/laugh_tests/colbeck1976/verification_data/runinfo.txt