Adjust Hooke internals to use unsafe YAML (not just builtin Python types).

Adjust Hooke internals to use unsafe YAML (not just builtin Python types).

Pros:
* More explicit YAML.
* Simple, robust code.
* Easily (de)serialize everything, regardless of nesting, etc.
Cons:
* Uglier YAML.

After wrestling with a yaml.safe_dump()able representation, I've given
up and shifted to yaml.dump().  Now we can dump anything easily, which
is great :).  For example, this will allow you to access polymer fit
parameters.  However, there will be things like
  !!python/object/new:hooke.playlist.FilePlaylist
in the output YAML files.  Such is life.

While I was at it, I ran
  $ nosetests --with-doctest --doctest-tests hooke/ 2>&1 | log
and cleaned up a number of the doctests.  Now the only things that
fail in there are the yet-to-be-upgraded submods left over from before
my rewrite.

I haven't checked test/ recently, that's next ;).