Convert URLs to XPath and pass through to the templating system.
If no 'page.htm' append 'default.htm' to xpath?
Handle blogposts specially.
Tests:
- site.com/path1/path2/page1.htm -> /webpages/folder[@name='path1']/folder[@name='path2']/webpage[@key='page1']
- site.com/path1/path2/ -> /webpages/folder[@name='path1']/folder[@name='path2']/webpage[@key='default']
- site.com /blogposts/yyyy/mm/dd/mypost.htm -> /blogpost[(@createdYear='yyyy' and @createdMonth='mm' and @createdDay='dd' and @key='mypost')]