ctn-waterloo/nengo — pull request #279 by arvoelke (2014-03-11 20:51:54+00:00)
Title: Maintain hierarchy in objects, and force `with` blocks

Redid next part of #265 on dd63c9bb5e4dddd4d07a469bd4076aba8b08ee70. The rest will come in separate PRs.

- `objects.Model/Network` -> `objects.Network`
- `with` is always required
- `builder.BuiltModel` -> `builder.Model`
- `NengoObject` base class for all non-builtin model objects
- Error checking in context management