#i122208# allow silgraphite build with a move-semantic enabled STL

by fixing the non-canonical copy constructor of gr::Segment()
WaE: compare unsigned values to prevent compiler warnings.
WaE: unsigned const to prevent compiler warnings.
WaE: Remove unused variable.
WaE: unname unused argument to prevent compiler warnings.
WaE: reorder initializations properly to prevent compiler warnings.
WaE: unname unused argument to prevent compiler warnings.
WaE: reorder initializations properly to prevent compiler warnings.
WaE: Remove unused variable.