[int, str, NoneType etc].__module__ is "__builtin__", not "builtins"
allow building docs to HtmlHelp and other embedded builds.
test_utils: add some edge cases to test_test_address
test_address: detect builtins correctly on Python 2.x and 3.x
Documentation fixes:

* add missing include for test_skips.rst
* use absolute paths for sphinx extension "include" directives - eliminates warnings.
* align sys.path additions compliant with Sphinx
Merge pull request #585 from jszakmeister/doc-fixes

Doc fixes
Merge pull request #579 from bfroehle/setup_install_nose_tools

Stop forgetting to install package 'nose.tools'.
Merge pull request #573
Merge pull request #563
Shunt any results of running a test case in Python 3.3.

In Python 2.x, running `case(result)` returned `None`.  In Python 3.3,
it now returns an object.  As a result of that change, some doctests
are failing with Python 3.3.  We don't care about the return value,
so let's just discard it by assigning it to an underscore.
Another doctest fix to work with Python 3.3.

In Python 3.3, it's quoting the module name with single quotes, which is
different than Python previous Python implementations.  Use the
ELLIPSIS feature to help match around it.
Fix an infinite recursion issue in Python 3.3.

Python 3.3 has introduced implicit namespace packages (PEP-420), which
means that some directories can get introduced that have the same base
component as the Python package as we're interested in.

In our case, the traverse namespace test has a support folder called
`namespace_pkg`, which has a directory called `namespace_pkg` and
`site-packages/namespace_pkg` underneath it.  All three directories are
now included in `namespace_pkg.__path__` due to PEP-420, where
previously only the latter two entries where.  This caused us to
repeatedly visit `support/namespace_pkg` over and over again.  To fix
this, we now keep track of which paths have been visited and avoid
re-visiting ones we've already examined.
Merge pull request #588 from jszakmeister/python-3.3-fixes

Python 3.3 fixes
Fix #134: Stop xunit from completely dying if it encounters an error

Since Python 3 has completely dropped supporting strings as exceptions,
the traceback.format_exception() function now dies when passed a string
as an exception value when the function attempts to access the
__context__ attribute.

The issue is that we can get a string for the exception value because of
the formatError() api.  The capture and logcapture plugins turn the
exception object into a string, add some data, and return the string.
Since that feels like part of the api that we offer, we'll teach xunit
to cope with strings as exception objects, even in Python 3, by having
our own custom format_exception.  This allows us to keep the nice
traceback, while still coping with exception value being a string.
Add a test for #134: Stop xunit from completely dying if it encounters an error
Merge pull request #591 from jszakmeister/fix-xunit-on-python-3

Fix #134: Stop xunit from completely dying if it encounters an error
Use `nose.__loader__` to load 'usage.txt', if available.

Previously we only used `nose.__loader__` if we thought
that the loader was zipimporter. Additionally, we use
`nose.__file__` to build the path to 'usage.txt' as
suggested by PEP-302.