Avoid long transaction note errors.

From plone/Products.Archetypes@f4372349ec31711bcdd42afdc4bdda1effdc30da
http://plone.293351.n2.nabble.com/FileStorageError-when-upgrading-Plone-4-0-9-gt-4-3-2-pending-td7567328.html
Reduce dependencies by moving some into an 'steps' extras_require.
pep8 and pyflakes cleanup
Add an upgrade step function that packs the ZODB.
Make changelog authors github links
Migrate from ``optparse`` to ``argparse``, make portal paths positional
Add options for controlling which profiles are upgraded.
Release 1.0rc1