[FEATURE] Log double Xclass registration

If there are two registrations for the same base class, the autoloader
log this sitation to TYPO3_CONF_VARS|AUTOLOADER|Log

Resolves: #60708
Change-Id: Ie23a213a8b3ca6e630089f0632d0ac4aa08a3f74
Reviewed-on: http://review.typo3.org/32023
Reviewed-by: Carsten Biebricher <cb@hdnet.de>
Reviewed-by: Tim Spiekerkötter <tim.spiekerkoetter@hdnet.de>
Tested-by: Tim Spiekerkötter <tim.spiekerkoetter@hdnet.de>