Downloads and meta ALPHA

This is an alpha build, it will likely have glaring errors which breaks
a lot of things.

Lots of changes have been introduced.
- Routes now have a dedicated config key
- Making disabling Xysti routes easier
- Download routes now introduced
- Downloads are now defined in a separate config file. Like the sitemap.

- page_meta() changed to meta()
- Could change sitemap.php to pages.php not sure atm? More likely to
conflict with other bundles.