MINOR add hook for extensions to update current page id, before falling back to default
Merge pull request #879 from sheadawson/833-currentPageID

Add hook for extensions to update current page id, before falling ...
ContentControllerSearchExtensionTest doesn't clean up after itself.

The problem is FulltextSearchable::enable() does two things:
It enables the extension, as well as sets the MySQL create table option
to MyISAM. Later tests run with the extension enabled, because it doesn't
get removed at the end of the test, but the table type is set back to
InnoDB when the test is reset and schema recreated.

This produces side-effects where later tests in a suite tries to run
ALTER TABLE on File and add fulltext indexes when the table type
is set to InnoDB, causing an error.
Merge pull request #880 from halkyon/fulltextsearch_text

ContentControllerSearchExtensionTest doesn't clean up after itself.
Default CMSMain to Versioned::reading_stage("Stage")

Regression caused by https://github.com/silverstripe/silverstripe-framework/pull/2585
NEW: Page types no longer require a controller, they can inherit the parent page type's

Use ClassInfo::ancestry() instead of get_parent_class()

Fall back to ContentController by default
Merge pull request #881 from kinglozzer/framework-1905-controller-inheritance

NEW: Page types no longer require their own controller (fixes silverstripe/silverstripe-framework#1905)