Initialize unused ghost cells of grid variables to a huge number to
avoid valgrind complaining during stats writing
Make Taylor-Green vortex work again
Renamed the 4th order Morinishi dir in the noneq TG
Make the nonequidistant TG vortex working again
Include the string class in advec
Merge branch 'cleanup' into masterupstream
Merge remote-tracking branch 'upstream/master'