Debian packaging cleanup

This fixes a lot of linting errors and warnings reported by lintian (debian package linter), all documented in the debian/changelog.

It also removes ${misc:Depends} which got introduced by @fredj due to a lintian message, although this lintian message is not coming up anymore. This broke my debian packages on Debian Squeeze pulling a non-package called upstart-jobs.
This PR also aligns the version number to the real git tag and package.json version number in the upstream repository.