acinclude.m4:
  added macro to check if dirent.d_namlen is defined
cmd-line-utils/libedit/config.h:
  added define for __attribute__
cmd-line-utils/libedit/readline.c:
  checked STRUCT_DIRENT_HAS_D_NAMLEN instead of
  old enumeration of problem platforms
configure.in:
  added checking if dirent has d_namlen member field