Factor code out of main.cc and main.i into a bunch of files

so things are organized in a more sensible manner.  Take apart
finalInit and expose the individual functions which are now
called from python.  Make checkpointing a bit easier to use.

--HG--
extra : convert_revision : f470ddabbb47103e7b4734ef753c40089f2dcd9d

src/python/SConscript

@@ -107,10 +107,11 @@ def swig_it(module):
                 '-o ${TARGETS[0]} $SOURCES')
     swig_modules.append(module)
 
-swig_it('main')
+swig_it('core')
 swig_it('debug')
 swig_it('event')
 swig_it('random')
+swig_it('sim_object')
 swig_it('stats')
 swig_it('trace')