Support for Python < 2.7.
Fix support for templated operators.

Currently symbols like this cause the tool to error out:

    boost::enable_if<foobar>::type operator<< <Bar>(Foo&)

bloat.py ends up baulking when it has chopped the symbol down to:

    type operator<< <Bar>(Foo&)

This commit fixes that.
Fix runtime error.

Change:

    "opt.cppfilt" -> "opts.cppfilt"
bloat.py: Fixup deeply nested typedefs.

This is just a hack to get visualisation "working" in the loosest sense of
the word. I'll investigate why the seems to be unmatched angle brackets
later.

At least, I believe this is a hack.