Added 2 more options for mime-type detection. We now detect if the Fileinfo PECL...

Added 2 more options for mime-type detection. We now detect if the Fileinfo PECL extension is available and use it (PHP 5.3+ will have this more commonly than older versions), then try and use the now deprecated mime_content_type, and finally resort to inferring the mime-type from the file extension. Also, now if all else fails, we will gracefully degrade functionality by not embedding resources with undeterminable mime-types.