POSIX-compliant common path finder thanks to Gilles at http://unix.stackexchange.com/questions/11379/indexing-and-modifying-bash-parameter-array/12087#12087
POSIX-compliant common path finder thanks to Gilles at http://unix.stackexchange.com/questions/11379/indexing-and-modifying-bash-parameter-array/12087#12087

sukhmel/linux.scripts,sukhmel/linux.scripts