Implement Data Use Agreement about ckandev

[pkdash]

This has been implemented. The data preview and download options are not displayed until the user checks the checkbox and then agrees to the displayed agreement. This is only for non-registered users and they have to agree to data use agreement once per session.

[AmberSJones]

This is working with one exception: If a user has agreed to the agreement and then logs out (so the the site is ostensibly being accessed by a non-registered user), they are still able to access the files. The checkbox for Data User Agreement is already checked.

[pkdash]

Yes, if the user leaves the browser session for anybody else to use then this is a problem. This can be solved by making the current user agree to data use agreement for each dataset.

[pkdash]

This may not be a problem anymore with the updated code.

[AmberSJones]

I'll work on testing this when we have a body of issues that are ready for testing.

[AmberSJones]

This issue is resolved. Closing.