I would like to see a function in glib to simplify a filename in one or more
of the following ways:

1. Remove "." components such as in "./foo" and "foo/./bar", but probably
   not in "foo/."

2. Get rid of double slashes as in "foo//bar", but not in "//foo/bar" (where
   it means something else).

2a. Syntactically remove ".." and the preceding component.
--or--
2b. Remove ".." if the preceding component is not a symlink.

3. Expand symlinks.

4. Make absolute.

I can code this up fairly easily if we can agree that it is a good idea
and agree on an API.