specs around GeneratesHtml
specs for Layout
return NullLayout if template file doesn't exist
Re-order GeneratesHtml params to be _.partial-friendly
Warn when Layout template is truthy but doesn't exist

In addition to still returning NullLayout for template files that don't
exist, also emit a warning.

But skip the warning if the template path is falsy
Apparently grunt.file.exists needs guarded
spec Posts
sandbox the module
spy alias
verify stubbed Post is created
pass along additional needed params to Post
extra verifications
better verification
insert new Posts object
eliminate helper method
Posts are automatically sorted
post comparator switched to time instead of fileName
Posts sorts itself so Site doesn't have to
spec cleanup
use stealth's spyOnConstructor

Needs a patch to spyOnConstructor that gives access to the fakeClass
(via 'spies'.constructor.fake)