core: Continue PieCrust3 refactor, simplify pages. The asset pipeline is still the only function pipeline at this point. * No more `QualifiedPage`, and several other pieces of code deleted. * Data providers are simpler and more focused. For instance, the page iterator doesn't try to support other types of items. * Route parameters are proper known source metadata to remove the confusion between the two. * Make the baker and pipeline more correctly manage records and record histories. * Add support for record collapsing and deleting stale outputs in the asset pipeline.

# Uncomment this if you want to set 'pretty_urls' to 'true'.
#RewriteEngine on

# If you're running from a sub-directory, uncomment the RewriteBase statement and
# change it to the sub-directory name you're using.
#RewriteBase /yourbase

# Don't rewrite requests to stuff that physically exists.
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]

# Rewrite all the rest through the gateway.
RewriteRule ^.*$ index.php [NC,L]

# Various other configuration stuff.
AddType text/css .less