Various Changes

- Added IDOutils package name variable, as it varies with distro.
- Added the option to install Icinga-CGI (Classic Icinga Web)
- Added "Apache" as the name of Group for RedHat distros.
- Added Icinga-Web package requirement.
- Removed broker_module from icinga.cfg. IDOutil idomod.so should be enabled using the module definition, i.e. using a package.
- Added variables to ido2db.cfg, to make it compatible with RedHat bassed distros as well.
- Fix concat dependency name.