sqlcatalog: Re-implement with sqla in a framework-y way

[Paul Everitt]

Make a new branch which reimplements the work on the sqlcatalog branch, but in a "framework-y" way:

- Convert to SQLAlchemy

- Some minimal tests that mock the database

- A "fill up the batch" approach to security filtering

Fill Up the Batch
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In the sqlcatalog branch, we don't store that actual ACL. We do, though, have a boolean column that stores whether the resource has a custom ACL (security_state).

The reasoning is that 98% plus of the content has no local ACL. It relies instead on the ACL of its context: the Blog class and the security settings on the community. Furthermore, for most views, we don't need to look at everything: only enough to fill the first batch.

Thus, I'm interested in an approach where we ask SQL for a batch-ful and, if any have a column value of security_state=true, run has_permission on that object. If it fails, throw it out of the batch.

I suspect you have lots of ninja SQLAlchemy tricks on how to do this, in a way that is testable.

[Paul Everitt (paul-agendaless)]

I believe, given the 3 months into this, that we can retire this effort. The other (non-framework-y) fixes are proceeding along nicely. It would be nicer to do this in a single way, but the project doesn't have much traction, so let's forego it.

[Paul Everitt (paul-agendaless)]

I believe we can declare this effort aborted.