The strtod_flags() function allowed for fine control of how to
parse strings. However, only two different modes were actually
used: ascii mode ("C" locale) and permissive mode (accept ","
and "." as decimal separator).
The former had already its own function name (ascii_strtod).
Make the latter a separatge function as well (permissive_strtod)
and remove all the flags rigmarole.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
