Clean up some comments.
Improve handling of label-less parameters.

Improve handling of label-less parameters by storing them as box attributes with
a default name of anon_param<N>, with integer N.
Improve handling of label-less boxes.

Improve handling of label-less boxes by giving them a default label of
anon_box<N>, with integer N.  This allows for recreation of the UI hierarchy as
intended by the DSP.
Prefix boxes with "b_" and parameters with "p_".

Prefix boxes with "b_" and parameters with "p_", so as to make it easier to
figure out what attributes do what.  This also prevents name-space clashes
between boxes and parameters, and between them and PythonUI attributes, e.g.,
"layout".
Tests: update addButton() test.
Move property definitions to right after __init__.
FAUST: remove the ffi and C properties.
Set up UI and meta-data in FAUST, not FAUSTDsp.

Set up the UI and the DSP's meta-data in the FAUST class instead of in FAUSTDsp.
This separates the low-level classes (FAUSTDsp, PythonUI and PythonMeta) more
strongly from one another and makes the role of the FAUST wrapper class more
clear.
Special case the first UI group/box as "ui".
Remove redundant suffix of label-less Boxes/Params.

Remove the redundant "_box"/"_param" suffixes from the attribute names of
label-less Boxes/Params, so that their full name becomes "b_anon<N>" and
"p_anon<N>", respectively.
PythonUI: update doc string.
PythonUI.Param: make zone getter/setter private.
Rename FAUSTDsp to PythonDSP.

This name makes more sense to me, since it is more consistent with the other
wrapper type names ("PythonMeta" and "PythonUI") and hence reflects the fact
that the class is a Python wrapper of a C data type.
Extend and improve the README.