Build-Depend on debhelper-compat, change to debhelper compat level 11.
Update d/compat to 10, increase debhelper version depedency.
Set debhelper compat level to 9.
Increase debhelper compat level to 8, build-depend on debhelper (>=8).
* Move to a minimized dh 7 rules file. * Add debian/compat file.