Fix infinite loop when user/group for -u/-g are invalid.

Fixes #6008
Fix another exception issue with FreeBSD.

Refs #6008
Update the INSTALL file.

Refs #5817
Build fix for Windows.

Refs #6008
Compat: Only dump host address{,6}, alias if set.

Fixes #6013
Add nested group support for {Host,Service,User}Group.

Fixes #5858
Fix JSON output for non-finite numbers.

Fixes #6015
Implement support for hosts in the agent component.

Refs #4865
Fix incorrect variable name in the auto-discovery script.

Refs #6008
Add group apply (creates object only once and sets membership).

Refs #5910
Fix icinga2-list-agents.

Refs #6008
Fix copyright.
Fix failed agent checks after restarts.

Refs #4865
Implement CLR-based checks.
Build fix for Windows.
Allow running Icinga 2 as a Windows service.

Refs #4865
Add missing ::Stop calls.

Refs #4865
Use full Git version tag for the MSI package.

Refs #4865
Build fix.

Refs #4865
GNU C++ pthread compiler option for AIX.

Ref. https://www.ibm.com/developerworks/aix/library/au-gnu.html

Fixes #5999

Signed-off-by: Michael Friedrich <michael.friedrich@netways.de>