Ckanext-privatedatasets

This release includes:
- Full compatibility with CKAN 2.3
- Fixed Selenium tests

**New features**:
- Replace flash message by an acquisition button attached to private datasets.

This version includes compatibility with CKAN 2.3. The extension should also work with older versions.

This release includes:
- Set creator as the user who is updating the allowed users list when the notification callback is called. This improvement solves a CKAN bug which makes the extension throws an exception when a dataset that belongs to an organization is updated and no user is logged in (even if the `ignore_auth` field is in the `context` object)

New feature:
- Acquire URL is now returned when users are searching for datasets using the API. Doing it, users can be redirected to the acquisition URL without using the user interface.

Bugs fixed:
- Not include resources in package_search when users are not allowed to show the dataset