This is utterly silly and breaks plenty of stuff - Witek, you CAN'T append
slashes to all hosts just because some silly referer needs it, everywhere
else we NEED the hosts without slashes!
The file URI encoding is done in translate_url() immediately after the call
to find_uri_protocol() [which also uses check_whether_file_exists()]. So it
only makes sense to use check_whether_file_exists() also here since this is
a potential ambiguous URL from the user.
This fixes handling of files like 'a?b' given the command line, reported by
rrowan. It broke (for the n-th time ;) in CVS version 1.317->1.318 back in
August. The fix preserves the intend of that patch, namely the intend to
optimize the number of calls to file_exists().
