Remove ScriptInterpreterObject.

This removes ScriptInterpreterObject from the codebase completely.
Places that used to rely on ScriptInterpreterObject now use
StructuredData::Object and its derived classes.  To support this,
a new type of StructuredData object is introduced, called
StructuredData::Generic, which stores a void*.  Internally within
the python library, StructuredPythonObject subclasses this
StructuredData::Generic class so that it can addref and decref
the python object on construction and destruction.

Additionally, all of the classes in PythonDataObjects.h such
as PythonList, PythonDictionary, etc now provide a method to
create an instance of the corresponding StructuredData type.  For
example, there is PythonDictionary::CreateStructuredDictionary.
To eliminate dependencies on PythonDataObjects for external
callers, all ScriptInterpreter methods now return only
StructuredData classes

The rest of the changes in this CL are focused on fixing up
users of PythonDataObjects classes to use the new StructuredData
classes.

llvm-svn: 232534