Fix incorrect handling of inflections in InflectedRoute

When inflecting plugin/controller names in URL params we must also
ensure that default values have been inflected in the same way or match
failures will occur.

Refs #4120
Fix named routes not being indexed for reverse routing.

While *generally* people will be using the named route, we also need to
store routes based on their normal name. This allows features like
PaginatorHelper to interact with custom routes.

Refs #4126
Fix incorrect doc block.
Merge pull request #4129 from cakephp/routing-fixes

Fix a few routing issues