s/nagios-plugins/monitoring-plugins/g

Fixes #5459
Fix some incorrect naming macros for monitoring plugins.

Refs ##5459
Update more wrong references to monitoring plugin developer guidelines.

Refs #5459
Fix more plugin urls.

Refs #5459
Merge branch 'master' into next

Conflicts:
	es/urls.ent
	fr/quickstart-icinga.xml
	fr/quickstart-idoutils.xml