Collective-upgrade

----------------

- Restore Python 2.6 compatibility.
[rpatterson]

----------------

- Add an upgrade step for cooking the resource registries. Useful when
encountering viewlet errors on the resource registry viewlets after an
upgrade.
[rpatterson]

-------------------

- Add options for controlling which profiles are upgraded.
[rpatterson]

- Migrate from ``optparse`` to ``argparse`` and move portal paths from an
option to a positional argument.
[rpatterson]

- Add an upgrade step function that packs the ZODB.
[rpatterson]

- Reduce dependencies by moving some into an 'steps' extras_require.
[rpatterson]

- Fix a transaction error when the transaction note becomes too large.
[rpatterson]

----------------

- Fix an import step bug when installing a Plone site into a fresh Zope
instance. Fixes 3. Thanks to href for the report. [rpatterson]

----------------

- Add export and import steps for reconciling users and groups between
two PluggableAuthService plugins, such as between existing
Plone-only users and a newly added LDAP plugin.
[rpatterson]

- Support Plone 4.3, tolerate a deleted KSS tool
[rpatterson]

----------------

- Fix upgrading "Products" namespace profiles without previous version numbers
[rpatterson]

- Fix upgrade step handling, was skipping steps
[rpatterson]

- Fix duplicate UUID cleanup
[rpatterson]

- Move broken object steps into a separate ZCML file, should be
optional and used with care
[rpatterson]

- Plone 4.2 compatibility
[rpatterson]