Correct parallel output: pvd files linked to vtu-parts seperated by ":"...

Correct parallel output: pvd files linked to vtu-parts seperated by ":" instead of "-" (the latter is written out by /grid/io/file/vtk/vtkwiter.hh/
=> closing flyspray #169
reviewed by Bernd

git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@9429 2fb0f335-1f38-0410-981e-8018bf24f1b0

dumux/io/vtkmultiwriter.hh

@@ -357,8 +357,8 @@ private:
         if (commSize_ > 1) {
             std::ostringstream oss;
             oss << "s" << std::setw(4) << std::setfill('0') << commSize_
-     	        << ":p" << std::setw(4) << std::setfill('0') << rank
-                << ":" << simName_ << "-"
+     	        << "-p" << std::setw(4) << std::setfill('0') << rank
+                << "-" << simName_ << "-"
                 << std::setw(5) << curWriterNum_;
             return oss.str();