docs issue #4421: drop icinga-nrpe references
docs issue #4422: add samples files for reference
docs isse #4422: add sample files; second part
Merge branch 'master' into next
docs issue #4554: update icinga web troubleshooting for timezones
Merge branch 'next' of ssh://git@git.icinga.org/icinga-doc into next
update nagios plugins url

fixes #4760
Merge branch 'master' into next
set dump_retained_host_service_states_to_neb=1 from #3838
wipe enable_sla
wipe timedevent* from idoutils docs

fixes #4487
add colon to illegal_object_name_chars

fixes #4704
fix icinga web install on debian stable

fixes #4644
update versions
update db_model from check_source and logentries object_id
docs issue #4730: add "show_partial_servicegroups" to cgi.cfg
docs issue #4690: add hint to views.xml config file
docs issue #4705: add "dump_customvar_status" to idomod.cfg
update whatsnew
fix versions and cleanup.