Breaking: #72022 - Removed class loading fallback in cObject

See forge#72022

Description

The method ContentObjectRenderer->isClassAvailable() was used internally to check for a TypoScript property plugin.tx_myextension_pi1.includeLibs that included a PHP file when class_exists() failed.

With TYPO3 CMS 7, the spl_autoload mechanism checks for all places within extensions, alternatively composer does this on build-time. All needed classes are known, making this check and the option obsolete.

The functionality was introduced in TYPO3 4.3 before autoloading was available, and has now been removed.

Impact

The option .includeLibs on a plugin TypoScript object has no effect anymore.