Add gui (python3-pyface, python3-traitsui) and preferences (configobj)
optional dependencies to Recommends; upstream made these no longer
required as of this release.

Update to upstream version '5.3.0'
with Debian dir bc28cb13ca90581edd1222c61b7fc2110fa85e3f

Update to upstream version '5.2.1'
with Debian dir bdcf00d92f81439cd4ae7c508eaa1a3d280fb63a

Closes: #1027503

Changes-By: lintian-brush
Fixes: lintian: installable-field-mirrors-source
See-also: https://lintian.debian.org/tags/installable-field-mirrors-source.html

Update to upstream version '5.1.0'
with Debian dir d8c3019483580f56851cb4edab5e6312bb11ccb1

Remove unnecessary constraints

See merge request !4

* Build-Depends: Drop versioned constraint on debhelper.
* python-apptools-doc: Drop versioned constraint on python-apptools in Replaces.
* python-apptools-doc: Drop versioned constraint on python-apptools in Breaks.

Changes-By: deb-scrub-obsolete

Fix some issues reported by lintian

See merge request !3

Changes-By: lintian-brush
Fixes: lintian: out-of-date-standards-version
See-also: https://lintian.debian.org/tags/out-of-date-standards-version.html

Changes-By: lintian-brush
Fixes: lintian: upstream-metadata-file-is-missing
See-also: https://lintian.debian.org/tags/upstream-metadata-file-is-missing.html