[Radiant] "Just before write" parse of pages in extensions.

[Jordon Bedwell]

Is there a class we can tap into with extensions to parse a page just
before write? Somebody wanted the HAML plugin fixed because he ran
into a gotcha with the system and HAML where HAML complains about page
parts and improper nesting so I wanted to get this fixed for him but
have no idea what class I should tap into to do that.