Improve com admittance

CMakeLists.txt

include/sot/talos_balance/com-admittance-controller.hh

include/sot/talos_balance/dummy-dcm-estimator.hh

python/sot_talos_balance/create_entities_utils.py

python/sot_talos_balance/test/test_comAdmittance.py

src/CMakeLists.txt

src/com-admittance-controller.cpp

src/dummy-dcm-estimator.cpp