Notable changes in 0.33.3 since 0.33.2

General

The performance of bup ls when columnating a large number of results should be much better.

bup fuse should no longer linger after its mount point has been unmounted: https://bugs.debian.org/1050040
bup --version should work again.
bup gc should no longer remove stale packfiles before it creates the new midx at the end of a run. This could cause midx to complain about missing files, e.g.:
```
  warning: index pack-....idx missing
```
bup will no longer (since 0.33) ignore BUP_DIR looking for a pack.packSizeLimit.
A VFS optimization of the handling of requests for specific names within a given tree has been restored.
Incorrect uses of some exception handling code designed for compatibility with Python 2 have been replaced with the built-in Python 3 equivalents.
Some client calls to super(CLASS, self) have been replaced by super() to avoid errors during __del__.

test-help should no longer hang when run interactively, and should no longer be affected by the current locale. Previously it might fail in a non-C locale.
The bup damage invocation in test-fsck has been made much more aggressive in order to avoid transient failures caused both by unpredictable par2 behavior and the (currently) probabilistic nature of the damage.
OpenBSD builds should no longer fail on -Werror related issues involving PROC_SELF_EXE.

Alain Cochard, Austin Schuh, Johannes Berg, Julian Smith, Lucas Nussbaum, Nix, Rob Browning, Rob Leslie, and Robert Edmonds