Removed before_render_file helper. Switched :page into a readonly call to :page_stack.last. We now support calling .body() and .summary() for other pages, without breaking rendering inside that depends on a 'page' reference.
Fixed bug in header parsing permitting newlines in markdown and slim files (\s vs [ \t]).
options[:anywhere] is now stripped prior to render time. options is now available as a local variable.