layout_for works again with objects as specified in the documentation and Rails 2.3 [#5357 state:resolved]

Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

Revert "require_dependency should require using the normal mechanism if possible to avoid double-requires"

This was causing double requires since 991cd59a was reverted.
This reverts commit 8bf79739.

adds URL to the body generated by the redirect macro in the routes mapper as per the RFC, extracts common test pattern into a test macro, adds a test to cover the :status option

quick hack: hijacks the predicate RDoc::Parser.binary? so that it does not consider a handful of ordinary Ruby files in the Rails tree as binary (and thus excluded from the API)