Pagination support

[tlienart]

Support for pages that contains essentially a list to have that list split across several pages. Could look something like the following

XX 

{{paginate 5}}
  {{some_list}}
{{end}}

YY

Where XX and YY (if non-empty) would be applied on all pages.

The result would be to generate the page (e.g. /blog/) as well as a bunch of children pages /blog/page/2/ ...

Some notes

• children pages would have the same page vars as the parent page
• title would be the same across pages (?) could maybe have auxiliary children-specific page vars (like for tags)

Stuff to figure out

• is there a similar abstraction for "archive" pages?