freetz_functions:
 * introduce new function symlinks-abs2rel - converts absolute symlinks to relative ones (s. USAGE within the function for more details)

freetz_mklibs:
 * replace in-place implementation with a call to the function above
 * refs r9874, refs #1976


git-svn-id: file:///var/svn/freetz/trunk@11469 149334a1-2f27-0410-a3b9-fc62619ac1e6