[Critical] Setting custom entity factories doesn't work

[Swader]

Due to a lapse in logic, the setCustomEntity method on the Diffbot class is always called without an argument if the setHttpClient isn't called beforehand.

Change

        if (!$this->getHttpClient()) {
            $this->setHttpClient();
            $this->setEntityFactory();
        }

to

        if (!$this->getHttpClient()) {
            $this->setHttpClient();
        }
        if (!$this->getEntityFactory()) {
            $this->setEntityFactory();
        }

everywhere for a fix.