Wrap layout rendering in one method: _render_layout (this should make partial instrumentation easier).

Instead of marking raw text in templates as safe, and then putting them through String#<< which checks if the String is safe, use safe_concat, which uses the original (internal) String#<< and leaves the safe flag as is. Results in a significant performance improvement.

The real use case it to make all of the following act the same:

  root 'store#index', :as => 'store'
  match '/' => 'store#index', :as => 'store'
  match '/', :to => 'store#index', :as => 'store'

The test case provided deviates from this in order to demonstrate all three
forms in a single set of test routes.
Signed-off-by: NJeremy Kemper <jeremy@bitsweat.net>

Routing: fix that route shorthand shouldn't ignore other options. Raise if :as option is given to root method since its name is always 'root'

Shift more responsibility from application class to its singleton instance. Treat instantiation and boot as separate steps. Use app.config rather than app.configuration.

Fixes "Rack-mount boot time is slow as shit" [#3567 state:resolved]

Signed-off-by: NYehuda Katz <wycats@Yehuda-Katz.local>

AC::Head now doesn't have an unfulfilled Rendering dependency, and instead works just fine standalone (which means that ConditionalGet also doesn't have a Rendering dependency)

Added ActionDispatch::Request#authorization to access the http authentication header regardless of its proxy hiding [DHH]

Added cookies.permanent, cookies.signed, and cookies.permanent.signed accessor for common cookie actions [DHH]

:to => redirect() can take a String using 1.9-style interpolation or proc that takes the path parameters as a Hash