Fix Debian package issues reported by lintian

[jmbowman]

Fix any of these that can be resolved quickly before the next release:

E: portabase changes: bad-distribution-in-changes-file unstable
W: portabase source: native-package-with-dash-version
E: portabase source: source-is-missing resources/help/translations/cs/sphinx.js line length is 4310 characters (>512)
E: portabase source: source-is-missing resources/help/translations/fr/sphinx.js line length is 4125 characters (>512)
E: portabase source: source-is-missing resources/help/translations/it/sphinx.js line length is 3969 characters (>512)
E: portabase source: source-is-missing ... use --no-tag-display-limit to see all (or pipe to a file/program)
W: portabase source: package-needs-versioned-debhelper-build-depends 10
W: portabase source: useless-autoreconf-build-depends autotools-dev
W: portabase source: ambiguous-paragraph-in-dep5-copyright paragraph at line 6
W: portabase source: missing-license-paragraph-in-dep5-copyright lgpl-2.1+ (paragraph at line 38)
W: portabase source: ancient-standards-version 3.9.3 (released 2012-02-23) (current is 4.1.4)
W: portabase source: debian-watch-file-in-native-package
W: portabase: description-synopsis-starts-with-article
W: portabase: embedded-javascript-library usr/share/portabase/help/ja/_static/jquery.js please use libjs-jquery
W: portabase: embedded-javascript-library usr/share/portabase/help/ja/_static/underscore.js please use libjs-underscore
W: portabase: manpage-has-errors-from-man usr/share/man/man1/portabase.1.gz 111: warning: numeric expression expected (got `a')
W: portabase: desktop-mime-but-no-exec-code usr/share/applications/portabase.desktop
W: portabase: command-in-menu-file-and-desktop-file portabase usr/share/menu/portabase:3