remove LGPL headers

CMakeLists.txt

doc/CMakeLists.txt

include/CMakeLists.txt

include/dynamic-graph/python/api.hh

include/dynamic-graph/python/exception-python.hh

include/dynamic-graph/python/interpreter.hh

src/CMakeLists.txt

src/convert-dg-to-py.cc

src/convert-dg-to-py.hh

src/dynamic-graph-py.cc

src/dynamic_graph/tools.py

src/entity-py.cc

src/exception-python.cc

src/exception.hh

src/factory-py.cc

src/interpreter.cc

src/link-to-python.hh.in

src/pool-py.cc

src/signal-base-py.cc

src/signal-caster-py.cc