* Merge from debian unstable. Remaining changes: - debian/control: keep on building with libradius1-dev to avoid pusing radiusclient-ng to main. - Don't depend on nagios-plugins-extra, we dont need qstat and fping in main. - debian/{control,rules}: add an enable hardened build for PIE. (Debian bug 542728). - Build with libmysqlclient-dev only. - debian/pluginconfig/nt.cfg: Fix syntax error. (LP: #595528)