This filter exactly mimics the behavior of the Perl filter so is a drop-in replacement.
The filter is not integrated yet since it requires the Perl-to-C storage layer interface coming in a future commit.
Remove "File" and "Driver" from object names so they are shorter and easier to keep consistent.
Also remove the "driver" directory so storage implementations are visible directly under "storage".
Removed the "anchor" parameter because it was never used in any calls in the Perl code so it was just a dead parameter that always defaulted to true.
Contributed by Cynthia Shang.
