crontab should be in user space

[Humphrey van Polanen Petel]

crontab is part of user data.
A fresh install will not touch user data, but will delete the crontab of the user.

The cron system might be according to specs, but it is in conflict with ubuntu principles.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: cron 3.0pl1-128ubuntu2
ProcVersionSignature: Ubuntu 4.10.0-42.46~16.04.1-generic 4.10.17
Uname: Linux 4.10.0-42-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.14
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Dec 17 14:22:45 2017
InstallationDate: Installed on 2017-12-13 (3 days ago)
InstallationMedia: Ubuntu 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
SourcePackage: cron
UpgradeStatus: No upgrade log present (probably fresh install)