see http://pulkomandy.tk/projects/GrafX2/ticket/82
fixes :
- Open_file_write() and Open_file_write_with_alternate_ext() when no unicode filename is supplied (WIN32)
- Store unicode filename for brush (all)
- Fixes the error red flash (Win32-GDI) and palette cycling
- window position saving (Win32-GDI)
also minor things