Fix incorrect return type for ScriptSignal::Invoke

refs #7744
Remove icinga-prepare-dirs from icinga-bin package

`icinga-prepare-dirs` was part of the package common and bin. Since it
was added with 2.2.0 to common with a man page I would expect this to be
the right place so I removed it from bin.

fixes #7740

Signed-off-by: Gunnar Beutner <gunnar.beutner@netways.de>
Refactor apply/object rules

fixes #7700
Implement a C++ code generator for libconfig

fixes #7699
fixes #7704
fixes #7706
Build fix

refs #7699
Fix some incorrectly generated code

refs #7699
Improve error messages for the config parser

refs #7699
Add notification custom vars to the satellite-{host,service} templates

fixes #7770
Split DynamicObject::OnConfigLoaded into two separate events

refs #7780
Make sure source information is always available for error messages

refs #7699
Fix initialization bug for the Endpoint class

refs #7780
Increase default timeout for NRPE checks

fixes #7747
Fix initialization for the ApiListener class

fixes #7780
Fix initialization bug for the Notification class

refs #7780
Refactor the stack frame handling for scripts

fixes #7748
Remove the C++ code generator

refs #7699
Fix the shift/reduce conflicts in the parser

fixes #7800
Improve test coverage for the array class
Fix incorrect result for the !in operator

fixes #7806
Implement unit tests for the config parser

refs #7805