FIX PHPUnit latest not working with composer installed builds

When using composer, we must rely on the composer autoloader to
load in PHPUnit and not try do to so ourselves, as the old
PHPUnit\Autoload.php file doesnt understand how to find things
in vendor
Merge pull request #1118 from silverstripe-rebelalliance/fix/phpunit/3.1

FIX PHPUnit latest not working with composer installed builds
BUG: Replaced extendedSQL/buildSQL with DataList as per ticket 8183

BUG: Correcting the4 case of a function

Corrcting the case of a function

BUG: replaced deprecated extendedSQL call with DataList->where
Add docs on how to customise the TinyMCE editor.

Fix whitespace problems.
Merge pull request #1126 from silverstripe-rebelalliance/open/8183

BUG: Replaced extendedSQL/buildSQL with DataList as per ticket 8183
Merge pull request #1127 from mateusz/tinymce-docs

Add docs on how to customise the TinyMCE editor.
Fixing code formatting in rich-text-editing docs
Fixing code formatting
Corrects indentation and line length
API HTTP::urlRewriter with (string)$code deprecated in 3.1. Fixed regressions and CSS urls.

urlRewriter will expect a callable as a second parameter,
but will work with the current api and simply raise a deprecation error.

HTTP::absoluteURLs now correctly rewrites urls into absolute urls. Resolves introduced in c56a80d6ce

HTTP::absoluteURLs now handles additional cases where urls were not translated.

Test cases for HTTP::absoluteURLs added for both css and attribute links.

Cleaned up replacement expression and improved documentation.
BUG Respect CMS preview active state (related to #8089)