Fix remaining Python issues leftover from my previous patch.

- The Swig post-processing scripts are now run.
- edit-swig-python-wrapper-file.py has been modified so it can be run
from the Makefile.
- The issue that prompted me to pass -classic to swig is fixed by this,
so -classic isn't passed anymore.

Python shouldn't complain anymore about a missing method 'FindDebuggerByID'
on the SBDebugger object whenever lldb is run.

llvm-svn: 132383