Basically, the intent is to do a modern (for C) interface which
allows reproducing the look and feel of uifc but without hurting
as much.

The intent is to support a tree of objects, each of which have
an attribute get/set function as their main interface.

Various callbacks will be supported for various object types, and
positioning will be relative to the "child area" of the parent.

The SyncTERM main screen is expected to look something like:
root
+--frame (dialing directory)
|  +--list
+--frame (settings)
|  +--list
+--textinput (comment)

Internally, the code is wildly type-unsafe, but there's an
auto-generated API (which is the only thing exported) that is
type-safe.

This also introduces the CuTest C test suite as an experiment.