Fix issues and improve spec for SLE submit request

https://spdx.org/licenses/

* Add Provides tag for user and groups

Following the guide https://en.opensuse.org/openSUSE:Packaging_guidelines#Users_and_Groups
as requested by our security team.

refs #6

Following this commit
https://github.com/Icinga/icinga2/commit/4970c459ee9fa09c4ab92a2553824f2586fb77f5
logrotate needs to be available during build for the correct
configuration to be installed.

Builds needed for:
* SLES 12
* Fedora 27

* Improve RPM groups
* Improve grammar in RPM subpackage descriptions
* Remove redundant %clean section from rpm spec
* Fix service.d dir which was not referenced by any package
* Use sle_version instead of deprecated leap_version
  see https://en.opensuse.org/openSUSE:Build_Service_cross_distribution_howto#leap_version_macro_.28deprecated.29
* Also add systemd limits file to openSUSE Tumbleweed
* Documentation should not hard-require the program
  as it is technically "usable" without it.

Dropping policyhelp for Fedora 27, was only needed on Fedora < 20, and EL < 7

See https://fedoraproject.org/wiki/SELinux_Policy_Modules_Packaging_Draft

refs #61

refs #61

Builds needed for:
* SLES 12
* Fedora 27

* Improve RPM groups
* Improve grammar in RPM subpackage descriptions
* Remove redundant %clean section from rpm spec
* Fix service.d dir which was not referenced by any package
* Use sle_version instead of deprecated leap_version
  see https://en.opensuse.org/openSUSE:Build_Service_cross_distribution_howto#leap_version_macro_.28deprecated.29
* Also add systemd limits file to openSUSE Tumbleweed
* Documentation should not hard-require the program
  as it is technically "usable" without it.

Dropping policyhelp for Fedora 27, was only needed on Fedora < 20, and EL < 7

See https://fedoraproject.org/wiki/SELinux_Policy_Modules_Packaging_Draft

refs #61

refs #61