.gitlab-ci.yml: run reprepro as 'build' user so that a potential 'reprepro removesrc' later does not fail

.gitlab-ci.yml: print BASESUITE, OURSUITE and REFORM_TOOLS_BRANCH at the end as gitlab CI does not show the set variables for jobs

changes from reform.d.n

See merge request !20

patches/gst-plugins-{good,bad}1.0: don't use patch but just append to make it not break when debian/patches/series gets changed

This reverts commit e06d05f3.

Firedecor

See merge request !19

Otherwise files get installed into /debian, i.e. a "debian" directory
gets placed in the root directory / as part of the installation.