Renamed CakeRequest::onlyAllow() to CakeRequest::allowMethod().

Existing name is unintuitive and it's not easily apparent what
the method does. Closes #2803
Updated bake templates to use CakeRequest::allowMethod()
Updated upgrade shell to change CakeRequest::onlyAllow() usages.
remove the upgrade shell

to be made into a seperate application
Merge pull request #2804 from ADmad/2.5-cakerequest

Renamed CakeRequest::onlyAllow() to CakeRequest::allowMethod().
Merge branch 'master' into 2.5

Conflicts:
	lib/Cake/Model/Permission.php
Merge pull request #2812 from AD7six/3.0-remove-upgrade

remove the upgrade shell
Merge branch '2.5' into 3.0

Conflicts:
	lib/Cake/Console/Command/UpgradeShell.php
	lib/Cake/Console/Templates/default/actions/controller_actions.ctp
	lib/Cake/Console/Templates/default/views/index.ctp
	lib/Cake/Core/App.php
	lib/Cake/Core/Object.php
	lib/Cake/Error/ErrorHandler.php
	lib/Cake/Model/Datasource/Database/Postgres.php
	lib/Cake/Model/Datasource/Database/Sqlserver.php
	lib/Cake/Model/Permission.php
	lib/Cake/Routing/Router.php
	lib/Cake/Test/Case/Model/Datasource/Database/PostgresTest.php
	lib/Cake/Test/Case/View/MediaViewTest.php
	lib/Cake/Test/bake_compare/Controller/ActionsWithNoSessions.ctp
	lib/Cake/View/MediaView.php
	src/Console/Command/Task/ControllerTask.php
	src/Event/EventManager.php
	src/Network/Request.php
	src/Network/Session.php
	src/Routing/Route/Route.php
	src/View/Helper/NumberHelper.php
	src/View/Helper/TimeHelper.php
	src/View/View.php
	tests/TestCase/Controller/Component/SessionComponentTest.php
	tests/TestCase/I18n/I18nTest.php
	tests/TestCase/Network/RequestTest.php
	tests/TestCase/View/Helper/FormHelperTest.php
	tests/TestCase/View/ViewTest.php