- Updated the system to work with modules.
- Updated module docs to consider namespacing.
- Fixed view loading and registration event ordering.
- Fixed checking if views are registered.
Changed the system out to be a theme event instead of method, to align
with other registration events, and so that the theme view work can
better be contained in its own class.
Adds a registration system via the logical theme system, to tell
BookStack about views to render before or after a specific template
is included in the system.
