BUG Fix format_exc() call

This was actually wrong in both Python 2 and 3, but error was only
triggered for 3.
BUG List comprehension instead of map()

In Python 3, map() returns an iterator, which is not what we want.
BUG Fix yet another str/bytes issue
PY3 Fix an interesting Python 3 incompatibility
MIN str.lower() works in python 3 and 2
BUG reduce is not builtin Python 3
BUG Fix remaining Python 3 issues

This time I checked with nose on local machine