Check_MK Werk 7088: omd update can now be performed without access to source version

ID: 7088 Title: omd update can now be performed without access to source version Component: Site Management Level: 2 Class: New feature Version: 1.6.0i1 The "omd update" procedure, which is used to perform a version update for a site, always needed access to the previous version, the new version and the site. Since this change it is now possible to perform an update without access to the old version. This is possible becase we copy the information that are needed to the Check_MK site during site creation. This new mechanism can only be used when updating FROM a site that already implements this werk. Technical detail: <ul> <li>The meta files are saved for the first time during "omd create"</li> <li>The meta files are updated to the new version during each "omd update"</li> <li>The files are copied to the sites <tt>.version_meta</tt> directory.</li> <li>The directory <tt>/omd/versions/[version]/skel is copied.</li> <li>The file <tt>/omd/versions/[version]/share/omd/skel.permissions is copied.</li> <li>A file <tt><tt>.version_meta/version</tt> is created.</li> <li>When an update is performed, the meta files are used if they are available and up-to-date. In case they don't fit these conditiones, the previous version files need to be available as before this werk.</li> <li>