- Renamed nb_nonzero slots to nb_bool
- Renamed __nonzero__ methods to __bool__
- update core, lib, docs, and tests to match

This removes some bogus debug stuff Jiwon accidentally left in last time.

See SF#1549670.
The compiler package has not yet been updated.

but looks like that was a problem before this change.

Closes patch #1500623.  Thanks, Collin Winter.

functools, and adjust docs etc.

traceback.py be closer to the built-in formatting.
A few unittests had to be fixed, too.

Don't use our own temp name creation (dbm).
Should be backported to 2.5.

Create a real zip iterator object; not using itertools.izip
(Brian Holmes).

import MAGIC number.

``python -m compileall -f`` is really handy for finding Python files that use
invalid syntax.

Still need to remove traces of the UNARY_CONVERT opcode.

optimization for it.

SyntaxError.

This is probably not the proper solution to this failing test, but removing the
test itself causes 19 other tests to fail for some odd reason because doctest
doesn't expect a complete traceback (or something; rather odd problem for just
removing a single test).

auto-generates this file will need to get fixed.

'<>'.