/** \brief get next path component in filepath
\param path_p pointer to path (updated to "next" entry if any)
/** \brief get next path component in filepath
\param path_p pointer to path (updated to "next" entry if any)
\param fname "short" filename (without path)
\param path the path (dir1:dir2,..) - ala Unix
\param base can be added to relative paths (NULL for no append)
\param fname "short" filename (without path)
\param path the path (dir1:dir2,..) - ala Unix
\param base can be added to relative paths (NULL for no append)