Fix standard_of() w.r.t. listg.
* include/vaucanson/algorithms/standard_of.hxx (Standard_OfVisitor): After concatenating to automata, and before erasing the obsolete initial state of the RHS, do not explicitly erase the transition leaving that initial state. This is useless because del_state() already does the work. This was bogus because del_transition invalidates the delta_iterator in the listg implementation. * include/vaucanson/algorithms/standard.hxx: Typos.