[BUGFIX] Added the storage field to the TCA for sysfolders.

The field disappeared in 4.5 and has now been added again.

Thanks to Rene Haflinger (Agentur Frontal) for sponsoring
this fix with 100 beers during the bug auction at T3BOARD11.

Change-Id: Id5419d1391e7952ce61d051100a8da7777741a17
Resolves: #25494
Reviewed-on: http://review.typo3.org/1368
Reviewed-by: Susanne Moog
Tested-by: Susanne Moog
Reviewed-by: Steffen Gebert
Tested-by: Steffen Gebert