getParent: Gets the string of the parent specified by this pathname
Description
 Gets the string of the parent specified by this pathname.
 This is basically, by default the string before the last path separator
 of the absolute pathname.
Usage
"getParent"(pathname, depth=1L, fsep=.Platform$file.sep, ...)
Arguments
pathname
A character string of the pathname to be checked. depth
An integer specifying how many generations up the
     path should go. Value
 Returns a character string if the parent exists, otherwise NULL.