Replace the boilerplate calls to :

Replace the boilerplate calls to :
resolve_dfspath() -> unix_convert() -> get_full_smb_filename() -> check_name()
with a new function filename_convert().
This restores the check_name() calls that had gone missing
since the default create_file was changed. All "standard"
pathname processing now goes through filename_convert().
I'll take a look at the non-standard pathname processing
next. As a benefit, fixed a missing resolve_dfspath()
in the trans2 mkdir call.
Jeremy.