postinst, control: silence ucf (and make it actually work?) with '--debconf-ok' and depend on ucf (>= 0.28) for that; remove unused 'preinst'; update from update-rc.d to insserv in maintainer scripts; disable initscripts *before* they are purged; use bash instead of sh in maintainer scripts because they contain bashisms (postinst: pattern substitution ${RET//,/}, postrm: brace expansion id_rsa{,.pub}, maybe more)

don't provide 'hostname' because it is usually provided by the operating system; make sure that 'hostname' is run before us and does not overwrite our hostname setting