new constant defined in dipylon.pro : READANDWRITE
documentation
improved the translation of Ovid_M_I_452_465
modified fixedparameters.h (added default_path_to_dipydocs) and dipylonui.h (added path_to_dipydocs). The program keeps in memory where is the last dipydoc directory loaded.
modified dipydoc.cpp : fixed a bug in DipyDoc::get_xml_repr(). The translation name is now correctly written.