load pages class in index.php, before any output

Need to set http_response_code before any html is output.
Send a 404 if no $content (issue #26)

Several other checks in place thoughout as well.

If nothing was found for the request, throw a 404.
Basic template for error page (issue #26)

Will fill out more later. Just a basic template to see that it's
working.
Do not minify when setting
Apply article style to [data-error] too
More work on error pages

Set title, description, keywords.

Slightly modified error page template includes img, link back
home, an error message, and a dump of url_parse()
More character...
Re-add tags for search engines.
Type cast | type hint all function arguments.

Attempt to force correct types wherever appropriate.

Use type hinting for arrays in arguments. In other cases, cast to required
datatype before it is ever used.

In some situations, this will result in more errors, but it will be better
in the long run.
Merge branch 'import' into dev
Merge branch 'dev'