Fix pedantic, -Wextra warnings.

include/dynamic-graph/debug.h

include/dynamic-graph/entity.h

include/dynamic-graph/factory.h

include/dynamic-graph/signal-base.h

include/dynamic-graph/signal.t.cpp

src/debug/debug.cpp

src/dgraph/import.cpp

src/dgraph/interpreter-helper.cpp

src/plugins/shell-procedure.cpp

src/shell/functions.cpp