LazFileUtils: (Try)CreateRelativePath: implement option to control wether Dest and Source
must always share a common base folder (being not the root directory).
For CreateRelativePath it defaults to True for backwards compatibility.


git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41452 4005530d-fff6-0310-9dd1-cebe43e6787f