Get rid of the Random context and add the support directly to python.

We don't currently use randomness much, so I didn't go too far, but
in the future, we may want to actually expose the random number values
themselves to python.  For now, I'll at least let you seed it.
While we're at it, clean up a clearly bad way for generating random
doubles.

--HG--
extra : convert_revision : df2aa8b58dd0d9c2a7c771668a760b2df8db1e11

src/python/SConscript

@@ -108,6 +108,7 @@ def swig_it(basename):
 swig_it('main')
 swig_it('debug')
 swig_it('event')
+swig_it('random')
 swig_it('trace')
 
 # Action function to build the zip archive.  Uses the PyZipFile module