0.4.0 Release

Written for ppa-dev-tools by Bryce Harrington on 2023-04-28

The main new feature for the 0.4 release is the --show-rdepends argument
for the ppa tests command. Reverse dependencies, build dependencies,
and installation dependencies can be identified for a given source
package using cached APT information. This list of packages will be
used to generate lists of autopkgtest triggers, which when run should
help identify issues that could get flagged in Britney2 runs. While
similar to functionality provided by Bileto+Britney2, it is a
lighterweight facsimile which doesn't handle special cases so should not
be considered an equivalent, just as a preliminary screen to catch basic
issues.

For now, users will need to create and maintain this cache by hand
(automatic caching is planned for 0.5). See the README for a suggested
rsync command to do this.

In addition, The `ppa set` command now supports a number of new command
line options. `--ppa-dependencies` allows you to specify that your PPA
can use the contents of one or more other PPAs to satisfy build
dependencies. The `--architectures` option now has some related options
`--all-architectures` and `--default-architectures` for "Give me
everything" and "Just the usual", respectively. The `--enable` and
`--disable` arguments control whether packages can be uploaded to the
PPA to build.

All of the options supported by `ppa set` can also be specified to `ppa
create` to allow specifying them at creation time.

Beyond these two features, notable bugfixes address problems with Ubuntu
release specification, improvements to the `ppa tests` output, and
various idiosyncrasies with command line arguments.