+ block_list() (in block.module): returns an array of block objects for
+ theme_blocks() (in theme.inc): uses block_list() and theme("block") to
actually render them.
+ Decouples blocks content and layout, allows block_list() to be used
for non-output purposes (think "pull").
+ Unifies naming in theme.inc: render_blocks()) didn't really fit there.
+ Puts block_list() in blocks.module where it logically belongs.
- Removed some cruft from the Xtemplate theme. Patch by Ax.