Update Redirecting section in Routing guide

 * The `redirect` hook is now deprecated in favor of `beforeModel` and `afterModel`.
Add back and bring up-to-date filtering section in Redirecting guide
Add section headers to Redirecting guide
Note that the redirect hook can be used the same as afterModel can
Move Object Model section closer to beginning of guides
Merge pull request #1002 from alexspeller/change-object-model-position

Move Object Model section closer to beginning of guides
Merge pull request #768 from balinterdi/update-redirecting-guide

Update Redirecting section in Routing guide