list builtins in DTB (ACTION-760 maybe done)

I put the list builtins into DTB.   

http://www.w3.org/2005/rules/wiki/DTB#Functions_and_Predicates_on_RIF_Lists

Most of them have some examples.  All the examples work in my list
handling code (which is really quite trivial -- I didn't implement
collations, which would complicate things slightly, though not very
much).

I didn't try to describe the domains, or formally describe the mapping
yet.  I'd love an example to work from --- it's not a kind of language
I'm comfortable with.

I made some design decisions where necessary and added deep-equal back
in (since datatype equality is usefully different from value-space
equality).  Obviously we can talk about any of those....

      - Sandro