imports: add known third party libraries
py3: Use double backslash instead of ur-string literals
i18n: Remove translate.i18n

This is currently unused. It is also causing problems on python 3 due to
the use of __builtins__. Since we don't really need it at the moment, it
is safe to remove.
py3: tests: Use double backslash instead of ur-string literals
trados: Use BeautifulSoup4 instead of obsolete version 3
py3: Add unicode() shims for Python 3
py3: Consistently use os.walk instead of os.path.walk.

os.path.walk is deprecated, and removed in Python 3. This requires a
minor behavioural change.
See: https://bugs.python.org/issue4601
py3: Always use cStringIO to import StringIO

StringIO.StringIO is obsolete.
When we'll move things fully towards Python 3 we might have to deal with
io.BytesIO instead of io.StringIO.
py3: storage: Replace some instances of dict.iteritems() by dict.items()

For our use case, they are interchangeable. On Python 3, we only have
access to dict.items()
misc: Drop dictutils.generalupper
misc/dictutils: Use keys() instead of iterkeys() where possible
docs: remove mention of docs, we do docs elsewhere now
docs: cPO merging is mostly done

While there are still bugs in cPO there are better ways to track this.
It is too expensive in terms of time to review and port any issues to
bugzilla so not bothering to port any of these. We'll do them when we
find them and find the time to fix them.
docs: track filter TODOs in bugzilla

Not bothering to port these to bugzilla.  They'll come up again if they
are important enough.
docs: see --timestamp
docs: we already insert proper Gettext PO header
docs: pretty sure this is fixed for OOo
docs: lets use bugzilla for these

Won't port them across either.
docs: covered in docs/developers/testing.rst