add --exclude-special-files to exclude fifos, symlinks, sockets, and
device files.

Change Windows mode to quote A-Z also.  (--windows-mode could be short
for "--exclude-special-files --chars-to-quote A-Z: --quoting-char ;
--windows-time-format").

Write some better selection test cases to test new Iterate_fast func.

Work on killtest code - avoid returning a failure when a file is
simply skipped.

---------[ Medium term ]---------------------------------------

Interpret a list of filenames in globbing form
(--include-globbing-filelist maybe).

Add --dry-run option (target for v1.1.x)

Add # of increments option to --remove-older-than

Restore only changed files

Make argument shortcut for cstream

Make --calculate-averages work with directory_statistics file.

---------[ Long term ]---------------------------------------

Think about adding Gaudet's idea for keeping track of renamed files.

Look into different inode generation techniques (see treescan, Dean
Gaudet's other post).