Functionality:
- Show vocabulary description in its page.
- Enhance permission check.
- Add validation for missing variable values on first install.
- Use url aliases when available
- Show every node related to a vocabulary in its content.

Theme:
- Do better theme integration (no patch).
- Show 'vocabulary/' content with a better theme.
- It is possible, do not set a fixed menu width.

Extra:
- Rework theme to adjust to 800 pixels (not a module goal).
