Make group() method in re module accept no arguments.
Fix Sk.misceval.objectRepr to print 'inf' and '-inf' correctly.
Make list_sort_ pass Python numbers, not Javascript numbers, to richCompareBool.
Make Sk.abstr.typeName return "<invalid type>" for JS objects.

This will help prevent confusing error messages.
Eliminate code in Sk.builtin.type that incorrectly handled JS objects.
Improve Sk.misceval.richCompareBool to make behave more like Python.

Remove redundant code and comments, as well as add more comments
to clarify what each major section accomplishes.

Fixes bnmnetp/skulpt#110 and fixes bnmnetp/skulpt#107.
Update dist.