For auto-generating help files we need `buildtools`, so we can't
exclude it from source package. Also, we now include our version
of `help2man`, so we no longer need it as a build dependency,
but instead directly depend on `perl`.
more things needed in some README.repo
cow.sh: make it compatible with xenial
set DIST for use with optional local .pbuilderrc, also in deb.sh
link linux/.pbuilderrc to ~/.pbuilderrc if it doesn't exist
