- Patch #232037 by pwolanin and flobruit: block_list() renders all blocks even...

- Patch #232037 by pwolanin and flobruit: block_list() renders all blocks even on 404.  Refactored the code a bit so ithere is a split between loading and rendering of blocks.  By doing so, we are no longer forced to render _all_ blocks if we know they won't be shown.  There is more room for improvement here, I believe, but this is an incremental improvement.