Lazy dehydra-style types from treehydra

[Benjamin Smedberg]

I just pushed a new library to libs/unstable/lazy_types.js which is like
dehydra_types.js: it takes a treehydra tree object and converts it to a
dehydra-style type object. But it uses lazy properties and prototypes to
perform the conversion instead of recursively performing the conversion all
at once.

This library is what I'm using for the finalizer analysis currently: it's
*much* faster than the early-bound method. The only problem I could foresee
is if script hangs on to these lazy type objects beyond a single method, it
can end up with invalid tree calls.

This library is pretty much untested, except for the real-world usage in the
finalizer analysis where it appears to be working correctly.

--BDS