* ~~to use/not use '--rootcmd="$PWD/debian/gain-root-command"'~~ (done)
* ~~to use/not set upstream/debian tarball file name to lower case~~ (done)
* ~~to use/not use lintian~~ (done)
* ~~do net set DEBMAIL to my adrelanos personal e-mail address if not set~~ (done)
* ~~make deb-clean: also delete `deb_dist` folder~~ (done)
* ~~make git-tag-sign (for devs: git tag sign latest debian/changelog version)~~ (done)
* ~~make git-tag-verify (for devs: verify latest git tag)~~ (done)
* ~~make git-tag-check (for devs: check if current git head is a signed git tag)~~ (done)
* ~~make git-commit-verify (for devs: check if current git head is a signed git commit)~~ (done)
* ~~make git-verify (dev devs: combination of tag-check and commit-verify)~~ (done)