Move headers in include/sot/core and rename .h into .hh.

include/CMakeLists.txt

include/sot/core/additional-functions.hh

include/sot/core/binary-int-to-uint.hh

include/sot/core/binary-op.hh

include/sot/core/clamp-workspace.hh

include/sot/core/com-freezer.hh

include/sot/core/constraint.hh

include/sot/core/contiifstream.hh

include/sot/core/control-gr.hh

include/sot/core/control-pd.hh

include/sot/core/debug.hh

include/sot/core/derivator.hh

include/sot/core/device.hh

include/sot/core/exception-abstract.hh

include/sot/core/exception-dynamic.hh

include/sot/core/exception-factory.hh

include/sot/core/exception-feature.hh

include/sot/core/exception-signal.hh

include/sot/core/exception-task.hh

include/sot/core/exception-tools.hh