doc: Update documentation for file and directory functions. * libinterp/corefcn/dirfns.cc(Fpwd, Freaddir, Fmkdir, Frmdir, Freadlink, Ffnmatch): Redo docstring. * libinterp/corefcn/dirfns.cc(Fcd): Redo docstring. Return previous working directory if nargout > 0. * libinterp/corefcn/dirfns.cc(Flink, Fsymlink, Frename): Redo docstring. Re-order return values so that highest numbered value is assigned first to avoid re-sizing octave_value_list each time. * libinterp/corefcn/syscalls.cc(Flstat, Fmkfifo, FS_ISREG, FS_ISDIR, FS_ISCHR, FS_ISBLK, FS_ISFIFO, FS_ISLNK, FS_ISSOCK): Redo docstring. * scripts/general/isdir.m: Add more xrefs to @seealso. * scripts/miscellaneous/copyfile.m: Add more xrefs to @seealso. * scripts/miscellaneous/dir.m: Redo docstring. * scripts/miscellaneous/ls.m: Add more xrefs to @seealso.m. * scripts/miscellaneous/movefile.m: Add more xrefs to @seealso.

FCN_FILE_DIRS += testfun

testfun_FCN_FILES = \
  testfun/__have_feature__.m \
  testfun/__printf_assert__.m \
  testfun/__prog_output_assert__.m \
  testfun/__run_test_suite__.m \
  testfun/assert.m \
  testfun/demo.m \
  testfun/example.m \
  testfun/fail.m \
  testfun/rundemos.m \
  testfun/runtests.m \
  testfun/speed.m \
  testfun/test.m

FCN_FILES += $(testfun_FCN_FILES)

PKG_ADD_FILES += testfun/PKG_ADD

DIRSTAMP_FILES += testfun/$(octave_dirstamp)