Separate post loading and post reloading logic.

We'll also want a page reloader, and it makes no sense to duplicate
the loader -> reloader functinality.
Fix up the comments in Post.Types.
Set up the Page type and Tabular instance.

This requires renaming some fields on Post from `__foo` to `__postFoo`,
which then means I need to change some uses of fields as accessors
from `__foo` to `view _foo`.
Fix a typo in the tag page router.
Don't close the <html> tag in templates/default-layout.html prematurely.
Pull out common post/page loader code and write a page loader.

This is sort of hacky, and if I wanted to be able to load more things,
I'd want to rethink it. But it works good enough for this.
There's no reason to make loaders return a table, so make them return lists.
Set up loader for pages.
Set up page routing (at /pageName) and rendering.
Rename Page to StaticPage everywhere.
Show a list of all static pages, sorted by slug.
Merge branch 'pages' (closes #3)